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Canola is an essential Canadian crop that generated a revenue of $14.4 B from its export in the 2022 fiscal year. To consistently export the best quality canola and set the correct pricing that truly reflects the grade, it is crucial to invest in reliable, high speed, and accurate grading technologies. Leveraging the current progress in Artificial Intelligence algorithms, this research proposes a comprehensive end-to-end system to detect damage to canola kernels and grade them. The proposed system comprises an accelerated sample preparation setup, custom-built specialized AI models, and an edge-AI microprocessor for in-field use. This thesis mainly focuses on the development of specialized neural networks to accurately detect damaged canola seeds as it is the most complex part of the system. Two foundational object detection networks, You Only Look Once (YOLO) version 5 and version 7 were optimized to be compatible with resource-constrained hardware environments. The aim of developing the two optimal networks was to mitigate trade-offs among speed, accuracy, cost, and model size, thereby creating a more balanced and optimized network. Several architectural design options were explored to compress the network structure of the two models in terms of size and cost yet retain or improve the metrics of accuracy and inference speed. The results from the design choices indicate that reconstructing YOLOv5 with ShuffleNet as the backbone reduces its size and cost and increases the inference speed but negatively affects the detection accuracy. Replacing the Convolutional Blocks present in the Spatial Pyramid Pooling Cross Stage Partial and all the Efficient Layer Aggregation Network modules of YOLOv7 with the Ghost Convolutional Network and adding two Convolutional Block Attention Modules improves both mean average precision metric compared to the parent model and reduces the size and cost. To prepare the samples faster, a semi-automatic option was adopted and its effect on d

The designs for a remote managed honey level and temperature control system for a beehive are presented in this thesis. These designs can be useful in beekeeping, as apiarists can have better understanding of environmental factors and stresses affecting the honeybee population. For monitoring honey level in the hive boxes, interdigitated capacitor sensors fabricated up on the frames in the hive box are presented. Simulations and experimental testing of prototypes are presented for measuring the level of honey on top of the frames. For the temperature control in the hive, various heater designs with performance simulations are presented to heat the brood in the hive to 35 ℃ regularly, and further increase temperature to kill Varro mites. This system will measure the temperature in each region of the frame board. If any mite is detected, the temperature will be increased on that region to kill the mite, and this can protect other honey regions from destroying and save energy. The prototype interdigitated capacitor sensors were built and experimentally tested in the lab to measure the level of water on the frames. They showed that the capacitance would increase with the level of water on top of the sensor from 1 mm to 10 mm. Electronics were constructed to record the data from the interdigitated capacitor sensors and record the data on an SD card.

We designed and implemented a hyperspectral microscope with structured illumination using the Olympus IX73 microscope as its basic platform. This system, which was designed and built in our Integrated Computational Optical Imaging Laboratory, combines two Digital Micromirror Devices (DMD) to compensate for the angular dispersion introduced by the blazed grating structure of the original DMD that was used to produce the structured illumination. Our hyperspectral microscope uses a supercontiuum laser illumination that can be spectrally filtered for desired wavelength ranges using an acoustic-optic filter. The system is controlled using LabVIEW, that allows for synchronous and asynchronous control of 1) illumination laser source, 2) acousto-optic filter, 3) spatial light modulator (DMD) and 4) camera. This LabView-based system control enables the implementation of a wide variety of image acquisition modes. Our microscope’s hyperspectral modality uses a wavelength-scanning configuration, where the supercontiuum laser illumination is filtered using an acousto-optic filter to produce very narrowband light for to acquire different hyperspectral images. Our system could be an excellent platform for implementing different types of hyperspectral data acquisition to implement, e.g., super-resolution microscopy and compressed sensing. The use of a DMD-based spatial light modulator allows for very fast spatial light modulation.

The designs for a remote managed honey level and temperature control system for a beehive are presented in this thesis. These designs can be useful in beekeeping, as apiarists can have better understanding of environmental factors and stresses affecting the honeybee population. For monitoring honey level in the hive boxes, interdigitated capacitor sensors fabricated up on the frames in the hive box are presented. Simulations and experimental testing of prototypes are presented for measuring the level of honey on top of the frames. For the temperature control in the hive, various heater designs with performance simulations are presented to heat the brood in the hive to 35 ℃ regularly, and further increase temperature to kill Varro mites. This system will measure the temperature in each region of the frame board. If any mite is detected, the temperature will be increased on that region to kill the mite, and this can protect other honey regions from destroying and save energy. The prototype interdigitated capacitor sensors were built and experimentally tested in the lab to measure the level of water on the frames. They showed that the capacitance would increase with the level of water on top of the sensor from 1 mm to 10 mm. Electronics were constructed to record the data from the interdigitated capacitor sensors and record the data on an SD card.

Canola is an essential Canadian crop that generated a revenue of $14.4 B from its export in the 2022 fiscal year. To consistently export the best quality canola and set the correct pricing that truly reflects the grade, it is crucial to invest in reliable, high speed, and accurate grading technologies. Leveraging the current progress in Artificial Intelligence algorithms, this research proposes a comprehensive end-to-end system to detect damage to canola kernels and grade them. The proposed system comprises an accelerated sample preparation setup, custom-built specialized AI models, and an edge-AI microprocessor for in-field use. This thesis mainly focuses on the development of specialized neural networks to accurately detect damaged canola seeds as it is the most complex part of the system. Two foundational object detection networks, You Only Look Once (YOLO) version 5 and version 7 were optimized to be compatible with resource-constrained hardware environments. The aim of developing the two optimal networks was to mitigate trade-offs among speed, accuracy, cost, and model size, thereby creating a more balanced and optimized network. Several architectural design options were explored to compress the network structure of the two models in terms of size and cost yet retain or improve the metrics of accuracy and inference speed. The results from the design choices indicate that reconstructing YOLOv5 with ShuffleNet as the backbone reduces its size and cost and increases the inference speed but negatively affects the detection accuracy. Replacing the Convolutional Blocks present in the Spatial Pyramid Pooling Cross Stage Partial and all the Efficient Layer Aggregation Network modules of YOLOv7 with the Ghost Convolutional Network and adding two Convolutional Block Attention Modules improves both mean average precision metric compared to the parent model and reduces the size and cost. To prepare the samples faster, a semi-automatic option was adopted and its effect on d

Image distortion is one of the most common problems of optical receivers. Adaptive Optics (AO) technology was invented to solve that issue for ground-based telescopes. The deformable mirror (DM) is the corrector which is being used to correct the aberrated received image in an AO system. The arrays of actuators and the flexible mirror face sheet are the two main elements of a DM. In this thesis, a tri-electrode electrostatic actuator was studied which is comprised of one moving MEMS electrode and two fixed controlling electrodes. The actuator is primarily beneficial for usage in an array of actuators for DMs, since only one common high-voltage electrode is employed as the background electrode for all actuators in the array, and the movement of each individual actuator can be controlled by an individual low voltage electrode. The tri-electrode topology, and the additionally presented extended electrode tri-electrode configurations, are designed such that they can be utilized for other applications such as MEMS switches. In this work, all the design parameters of the tri-electrode actuator were studied in simulation using the finite element method and restoring spring force method, as well as experimentally. The design studies were dimensionless. Therefore, the optimizations can be used for an actuator of any size. The studies showed that the controlling voltage of the actuator can be decreased significantly. For one specific design, it was shown that the controlling voltage is almost four times smaller than for a conventional parallel plate electrostatic actuator. The maximum displacement of the actuator can be enhanced significantly compared to that of the conventional configuration. The increased range of motion can be bidirectional, and for one specific case it was 2.5 times larger than for the conventional actuator using the extended electrode design. Two silicon MEMS actuators were designed in order to experimentally verify the simulation studies. The measuremen

Studying fundamental symmetries at low and intermediate energies helps garner a more complete understanding of the Standard Model. In particular, atomic parity-violation tests the Standard Model at some of the lowest energies. Past results in cesium have provided the most accurate results for atomic parity-violation to date. Present results in ytterbium are reaching the accuracy levels of cesium, but have difficulties reconciling with theory due to complex atomic structures. This is why a proposed atomic parity-violation experiment in francium at TRIUMF could be advantageous. Parity-violating effects scales as ~ Z^2N, which favours francium (Z=87). Additionally, the hydrogen-like electronic configuration lends itself nicely to theoretical calculations. Furthermore, using the 7s-8s transition in francium to probe parity-violating effects is preferred due to heavily suppressed optical transitions, the caveat being the parity-violating transition is still smaller. The solution is to pair the parity-violating transition with a tunable Stark-induced transition in an interference experiment. However, coexisting with the parity-violating and Stark-induced transition is a small magnetic dipole transition. The 7s-8s transition is typically magnetic dipole forbidden, as it violates certain atomic selection rules. Nevertheless, due to the hyperfine interaction and relativistic effects there is a small mixing of states that allows for a magnetic dipole transition. Understanding this effect in francium is key for an atomic parity-violation experiment and for testing atomic theory. To date, cesium is the only alkali in which the magnetic dipole transition has been studied. The cesium results for the relativistic contribution to the magnetic dipole transition differs from theory by 15%. Hence, on our way to measure parity-violation we want to also investigate the magnetic dipole transition in francium. To do this we need to implement some key components to the existing apparatus t

Studying fundamental symmetries at low and intermediate energies helps garner a more complete understanding of the Standard Model. In particular, atomic parity-violation tests the Standard Model at some of the lowest energies. Past results in cesium have provided the most accurate results for atomic parity-violation to date. Present results in ytterbium are reaching the accuracy levels of cesium, but have difficulties reconciling with theory due to complex atomic structures. This is why a proposed atomic parity-violation experiment in francium at TRIUMF could be advantageous. Parity-violating effects scales as ~ Z^2N, which favours francium (Z=87). Additionally, the hydrogen-like electronic configuration lends itself nicely to theoretical calculations. Furthermore, using the 7s-8s transition in francium to probe parity-violating effects is preferred due to heavily suppressed optical transitions, the caveat being the parity-violating transition is still smaller. The solution is to pair the parity-violating transition with a tunable Stark-induced transition in an interference experiment. However, coexisting with the parity-violating and Stark-induced transition is a small magnetic dipole transition. The 7s-8s transition is typically magnetic dipole forbidden, as it violates certain atomic selection rules. Nevertheless, due to the hyperfine interaction and relativistic effects there is a small mixing of states that allows for a magnetic dipole transition. Understanding this effect in francium is key for an atomic parity-violation experiment and for testing atomic theory. To date, cesium is the only alkali in which the magnetic dipole transition has been studied. The cesium results for the relativistic contribution to the magnetic dipole transition differs from theory by 15%. Hence, on our way to measure parity-violation we want to also investigate the magnetic dipole transition in francium. To do this we need to implement some key components to the existing apparatus t

Image distortion is one of the most common problems of optical receivers. Adaptive Optics (AO) technology was invented to solve that issue for ground-based telescopes. The deformable mirror (DM) is the corrector which is being used to correct the aberrated received image in an AO system. The arrays of actuators and the flexible mirror face sheet are the two main elements of a DM. In this thesis, a tri-electrode electrostatic actuator was studied which is comprised of one moving MEMS electrode and two fixed controlling electrodes. The actuator is primarily beneficial for usage in an array of actuators for DMs, since only one common high-voltage electrode is employed as the background electrode for all actuators in the array, and the movement of each individual actuator can be controlled by an individual low voltage electrode. The tri-electrode topology, and the additionally presented extended electrode tri-electrode configurations, are designed such that they can be utilized for other applications such as MEMS switches. In this work, all the design parameters of the tri-electrode actuator were studied in simulation using the finite element method and restoring spring force method, as well as experimentally. The design studies were dimensionless. Therefore, the optimizations can be used for an actuator of any size. The studies showed that the controlling voltage of the actuator can be decreased significantly. For one specific design, it was shown that the controlling voltage is almost four times smaller than for a conventional parallel plate electrostatic actuator. The maximum displacement of the actuator can be enhanced significantly compared to that of the conventional configuration. The increased range of motion can be bidirectional, and for one specific case it was 2.5 times larger than for the conventional actuator using the extended electrode design. Two silicon MEMS actuators were designed in order to experimentally verify the simulation studies. The measuremen

Oil- impregnated cellulose materials (such as Kraft paper) form an essential part of a transformer insulation system. The mechanical strength of the Kraft paper directly impacts the safe operation of the power transformer. Obtaining both spatially localized absorption profiles and subsurface structural images of the transformer paper would offer considerably more information about the samples than those obtained from optical methods such as microscopy. This could allow a continuous estimation of the operational age of the transformer insulation, beyond only classifying it as belonging to a broad age group. In this thesis, optical coherence tomography (OCT), a novel and non-invasive diagnostic technique, is used for the first time to acquire subsurface images of the thermally aged Kraft paper samples. To achieve this goal, we implemented a swept-source quadrature OCT (SS-QOCT) system for both structural and spectroscopic OCT image acquisition. Then frame theory was used to develop a generalized OCT image reconstruction method using redundant and non-uniformly spaced frequency domain samples. We also introduced a new concept of applying compressed sensing techniques to acquire a sample's spectroscopic properties, (i.e., its spatially localized light absorption profile). As the typical number of samples acquired by OCT was not sufficient for this purpose, we developed a gradient-based multidimensional signal recovery from incomplete samples in arbitrary separable dictionaries to reduce the number of required measurements for successful spectroscopic signal recovery. Then accelerated thermal ageing was used to generate samples of oil-impregnated Kraft paper with different levels of deterioration. From these aged paper samples, subsurface structural images at different depths were obtained using swept-source optical coherence tomography (SS-OCT). Statistical texture analysis was applied to these OCT images to convert each image into a spatial grayscale level dependence m

Multidimension functions frequently appear in Fourier Optics. For example, in a polychromatic optical system, one could have three spatial dimensions for space, one dimension for time, and one dimension for wavelength. Such systems would require multi-dimension mathematical models that could be efficiently analyzed or solved using Tensor Analysis. In Fourier Optics, convolution describes light propagation in multidimensional linear shift-invariant media and image formation in multidimensional linear shift-invariant imaging systems. In Tensor Analysis, many tensor operations, including convolution, are well defined in the literature. However, in this literature, tensor convolution is defined under three limiting assumptions 1) tensors to be convolved must have the same size; 2) tensors are expected to be convolved along all its dimensions; 3) tensors to be convolved should represent the same physical variables on each of its dimensions. In practice, one could possibly seek convolution along a specific subset of physical variables, which would not be well defined by this standard definition of tensor convolution. In this thesis, to overcome these limitations inherent in the definition of tensor convolution, we defined arbitrary mode-n convolution that allows convolution of different size tensors along a specific subset of their physical variables. We then applied our novel arbitrary mode-n convolution method to simulate three simple multidimensional Fourier Optics problems, i.e., free space propagation, diffraction by an aperture, and imaging using a thin lens. We simulated these problems using 1) full-sized tensors; 2) Tensor Tucker Decomposition; and 3) Tensor Train Decomposition. Our numerical results demonstrated that the Tensor Train approach is most efficient in terms of accuracy, storage requirement, and computation time.

Multidimension functions frequently appear in Fourier Optics. For example, in a polychromatic optical system, one could have three spatial dimensions for space, one dimension for time, and one dimension for wavelength. Such systems would require multi-dimension mathematical models that could be efficiently analyzed or solved using Tensor Analysis. In Fourier Optics, convolution describes light propagation in multidimensional linear shift-invariant media and image formation in multidimensional linear shift-invariant imaging systems. In Tensor Analysis, many tensor operations, including convolution, are well defined in the literature. However, in this literature, tensor convolution is defined under three limiting assumptions 1) tensors to be convolved must have the same size; 2) tensors are expected to be convolved along all its dimensions; 3) tensors to be convolved should represent the same physical variables on each of its dimensions. In practice, one could possibly seek convolution along a specific subset of physical variables, which would not be well defined by this standard definition of tensor convolution. In this thesis, to overcome these limitations inherent in the definition of tensor convolution, we defined arbitrary mode-n convolution that allows convolution of different size tensors along a specific subset of their physical variables. We then applied our novel arbitrary mode-n convolution method to simulate three simple multidimensional Fourier Optics problems, i.e., free space propagation, diffraction by an aperture, and imaging using a thin lens. We simulated these problems using 1) full-sized tensors; 2) Tensor Tucker Decomposition; and 3) Tensor Train Decomposition. Our numerical results demonstrated that the Tensor Train approach is most efficient in terms of accuracy, storage requirement, and computation time.

In this thesis, a micromachined electrostatic actuator is proposed for a deformable mirror system that is designed to achieve a decent stroke (~10 µm) with a reasonable resonant frequency (>1 kHz) and a controlling voltage smaller than 30 V, which is fully compatible with existing ICs. This is achieved by employing an Al / SU-8 phase sheet that is less stiff than a single crystal silicon phase sheet; a spiral electrostatic actuator that separates the stiffness, the resonant frequency, and the drive voltage at a certain displacement; and finally a novel tri-electrode topology of the electrostatic actuator that replaces the drive voltage of a conventional electrostatic actuator with a high static drive voltage and a low varying controlling voltage just a fraction of the conventional drive voltage. All three parts of the design were proven to be functional as desired via simulation. Both the polymer phase sheet and the spiral actuator design were fabricated, and shown a similar performance to the simulation. A prototype electrostatic actuator with tri-electrode topology was also fabricated and tested, demonstrating performance as desired.

In this thesis, a micromachined electrostatic actuator is proposed for a deformable mirror system that is designed to achieve a decent stroke (~10 µm) with a reasonable resonant frequency (>1 kHz) and a controlling voltage smaller than 30 V, which is fully compatible with existing ICs. This is achieved by employing an Al / SU-8 phase sheet that is less stiff than a single crystal silicon phase sheet; a spiral electrostatic actuator that separates the stiffness, the resonant frequency, and the drive voltage at a certain displacement; and finally a novel tri-electrode topology of the electrostatic actuator that replaces the drive voltage of a conventional electrostatic actuator with a high static drive voltage and a low varying controlling voltage just a fraction of the conventional drive voltage. All three parts of the design were proven to be functional as desired via simulation. Both the polymer phase sheet and the spiral actuator design were fabricated, and shown a similar performance to the simulation. A prototype electrostatic actuator with tri-electrode topology was also fabricated and tested, demonstrating performance as desired.

The main intent of multiple shape tracking is to allocate distinct track identities for all the salient shapes in a video sequence. The approach used in this problem is ‘Track by Detection’ scheme, where it needs to first, find shapes in a frame, map shapes to appropriate tracking tracks, and maintain the data continuity model throughout the video sequence. This thesis proposes a process to address shape tracking by maintaining a data continuity model based on shape relative proximity, shape context descriptor, and spatial color variation of a shape. Shape intersection is used to calculate the shape proximity. A spatial color analyzer is used to compare shape’s color variations between two consecutive frames, and shape similarity comparison is done by using the shape context descriptor. These values are then used to build and maintain the data continuity model throughout the video sequence. Besides, this also introduces a methodology to reestablish tracking identity when the detection is failed or occluded temporarily between small numbers of frames. The proposed method can be implemented using both online and offline approaches. To assess the proposed method’s robustness, we evaluated the online method in both VOT-ST2020 (Visual Object Tracking Challenge - Short Term) and MOT20 (Multiple Object Tracking) benchmark datasets. It was observed that in both benchmarks, the proposed approach can deliver state-of-the-art results.

Time domain spectroscopy with terahertz (THz) pulses is a powerful technique in characterizing material properties. THz technology is still developing and many optical components in this electromagnetic spectrum are not yet so economically available. We construct a THz spectrometer utilizing ultrashort laser pulses in nonlinear crystals that allows phase-resolved detection of light in the bandwidth 0.25-2.25 THz. Using our instrument, we examine spectral features of ordinary low loss materials which are later exploited in the study of multilayered dielectric structures designed to serve as low-cost optics for THz light. We develop wideband antireflection (AR) coatings for a variety of substrates with commercially available films and tapes. Utilizing multilayered structures, we propose the design of an economic, yet efficient, THz linear polarizer. In addition, we designed and constructed distributed Bragg reflectors which are incorporated in building a tunable Fabry-Perot cavity. With the aid of an AR coated electro-optic crystal, high resolution time domain spectroscopy performed on room temperature magnetoelectric multiferroic, BiFeO3 (BFO), showed the presence of electromagnon resonances in the sub-THz range. BFO is a potential material for the study of strong light matter coupling, which can have a substantial technological impact. We have tried tuning the resonances of BFO with applied electric field and optical heating in order to observe polariton modes. Due to the challenges in tuning BFO magnons, we investigate the design aspects of a high Q cavity for the discovery of a hybrid quasiparticle at room temperature, cavity magnon polariton (CMP), in the promising multiferroic. We have performed calculations showing both frequency and time domain response of the empty cavity system to highlight experimental implications for our apparatus. The tools developed in this thesis will be used in the study of CMP in BFO in a future project alongside other research.

The main intent of multiple shape tracking is to allocate distinct track identities for all the salient shapes in a video sequence. The approach used in this problem is ‘Track by Detection’ scheme, where it needs to first, find shapes in a frame, map shapes to appropriate tracking tracks, and maintain the data continuity model throughout the video sequence. This thesis proposes a process to address shape tracking by maintaining a data continuity model based on shape relative proximity, shape context descriptor, and spatial color variation of a shape. Shape intersection is used to calculate the shape proximity. A spatial color analyzer is used to compare shape’s color variations between two consecutive frames, and shape similarity comparison is done by using the shape context descriptor. These values are then used to build and maintain the data continuity model throughout the video sequence. Besides, this also introduces a methodology to reestablish tracking identity when the detection is failed or occluded temporarily between small numbers of frames. The proposed method can be implemented using both online and offline approaches. To assess the proposed method’s robustness, we evaluated the online method in both VOT-ST2020 (Visual Object Tracking Challenge - Short Term) and MOT20 (Multiple Object Tracking) benchmark datasets. It was observed that in both benchmarks, the proposed approach can deliver state-of-the-art results.

Time domain spectroscopy with terahertz (THz) pulses is a powerful technique in characterizing material properties. THz technology is still developing and many optical components in this electromagnetic spectrum are not yet so economically available. We construct a THz spectrometer utilizing ultrashort laser pulses in nonlinear crystals that allows phase-resolved detection of light in the bandwidth 0.25-2.25 THz. Using our instrument, we examine spectral features of ordinary low loss materials which are later exploited in the study of multilayered dielectric structures designed to serve as low-cost optics for THz light. We develop wideband antireflection (AR) coatings for a variety of substrates with commercially available films and tapes. Utilizing multilayered structures, we propose the design of an economic, yet efficient, THz linear polarizer. In addition, we designed and constructed distributed Bragg reflectors which are incorporated in building a tunable Fabry-Perot cavity. With the aid of an AR coated electro-optic crystal, high resolution time domain spectroscopy performed on room temperature magnetoelectric multiferroic, BiFeO3 (BFO), showed the presence of electromagnon resonances in the sub-THz range. BFO is a potential material for the study of strong light matter coupling, which can have a substantial technological impact. We have tried tuning the resonances of BFO with applied electric field and optical heating in order to observe polariton modes. Due to the challenges in tuning BFO magnons, we investigate the design aspects of a high Q cavity for the discovery of a hybrid quasiparticle at room temperature, cavity magnon polariton (CMP), in the promising multiferroic. We have performed calculations showing both frequency and time domain response of the empty cavity system to highlight experimental implications for our apparatus. The tools developed in this thesis will be used in the study of CMP in BFO in a future project alongside other research.

The resonant ionization laser ion source is an element-selective, efficient and versatile ion source which generates radioactive ion beams at on-line mass separator facilities. Elements with complex atomic structures and incomplete spectroscopic data require ionization scheme development. A grating-tuned titanium:sapphire (Ti:Sa) laser was used in applications for spectroscopy studies. A regiment of automated and continuous frequency-doubled and frequency tripled scans was developed to investigate different energy regions and electronic configurations of the elements. An intra-cavity frequency doubled chromium:forsterite laserwas built, to cover the spectral gap between the orange and red wavelengths as these are not attainable using Ti:Sa lasers. Laser resonance ionization spectroscopy has been performed on lanthanum (La) and thulium (Tm) at TRIUMF’s off-line laser ion source test stand to identify the highest efficiency ionization scheme for delivery of radioactive ion beams. Upon identification of possible two-step Ti:Sa laser based ionization schemes, systematic laser resonance ionization spectroscopy was performed by conducting laser scans across Rydberg states, ionization potentials, and auto-ionizing states. The spectroscopy of high-lying Rydberg states and auto-ionizing Rydberg states allowed to confirm and remeasure the ionization potential of Tm and La atom with improved accuracy. In-source resonance ionization spectroscopy of the purely radioactive astatine (At) atom was performed at the ISAC/TRIUMF radioactive ion beam facility to search for an efficient ionization scheme throughout auto-ionizing states. Apart from developing and implementing resonance ionization spectroscopy (RIS) schemes for elements, the issue of isobaric contamination in radioactive ion beam (RIB) delivery was addressed. On the newly implemented ion guide laser ion source (IG-LIS) for isobarically pure i ii RIB, operating modes and parameters were being developed and optimized. Desig

The resonant ionization laser ion source is an element-selective, efficient and versatile ion source which generates radioactive ion beams at on-line mass separator facilities. Elements with complex atomic structures and incomplete spectroscopic data require ionization scheme development. A grating-tuned titanium:sapphire (Ti:Sa) laser was used in applications for spectroscopy studies. A regiment of automated and continuous frequency-doubled and frequency tripled scans was developed to investigate different energy regions and electronic configurations of the elements. An intra-cavity frequency doubled chromium:forsterite laserwas built, to cover the spectral gap between the orange and red wavelengths as these are not attainable using Ti:Sa lasers. Laser resonance ionization spectroscopy has been performed on lanthanum (La) and thulium (Tm) at TRIUMF’s off-line laser ion source test stand to identify the highest efficiency ionization scheme for delivery of radioactive ion beams. Upon identification of possible two-step Ti:Sa laser based ionization schemes, systematic laser resonance ionization spectroscopy was performed by conducting laser scans across Rydberg states, ionization potentials, and auto-ionizing states. The spectroscopy of high-lying Rydberg states and auto-ionizing Rydberg states allowed to confirm and remeasure the ionization potential of Tm and La atom with improved accuracy. In-source resonance ionization spectroscopy of the purely radioactive astatine (At) atom was performed at the ISAC/TRIUMF radioactive ion beam facility to search for an efficient ionization scheme throughout auto-ionizing states. Apart from developing and implementing resonance ionization spectroscopy (RIS) schemes for elements, the issue of isobaric contamination in radioactive ion beam (RIB) delivery was addressed. On the newly implemented ion guide laser ion source (IG-LIS) for isobarically pure i ii RIB, operating modes and parameters were being developed and optimized. Desig

Diode-pumped solid-state lasers are highly recommended for a variety of industrial and scientific applications as they can offer high efficiency and excellent beam quality. However, power scaling of these lasers is a challenging task. The main limitation in power scaling of famous neodymium doped lasers such as Nd:YVO4 is the thermal lensing effect. Thermal lensing degrades the output beam quality and in extreme cases can result in crystal fracture. One potential solution to this problem is to reduce the induced heat load inside the gain media by decreasing the quantum defect. This was demonstrated successfully for the Nd:YVO4 laser by pumping the laser at a long wavelength of 914 nm instead of the traditional pumping at 808 nm wavelength. Among the Nd-doped crystals operating in the near infrared range, the crystal of yttrium lithium fluoride (Nd:YLF) is another interesting gain medium as it has the benefits of natural birefringence (can generate naturally polarized laser beam), negative dn/dT (reduces thermal effects) and long upper level lifetime (in favor of Q-switched operation). In this work we used a long wavelength pumping approach and for the first time examined the performance of a continuous-wave Nd:YLF laser at 1047 nm under 908 nm diode pumping. This pumping wavelength reduced the quantum defect by 50% as compared to the conventional 808 nm pumping. The laser produced an output power of 850 mW at 1047 nm with excellent beam quality and 625 mW at 1053 nm. The slope efficiency was ~73.9% and 46% for 1047 and 1053 nm, respectively. Therefore, a considerable power scaling is possible for Nd:YLF crystals owing to the strongly reduced quantum defect and, hence, thermal lensing.

Diode-pumped solid-state lasers are highly recommended for a variety of industrial and scientific applications as they can offer high efficiency and excellent beam quality. However, power scaling of these lasers is a challenging task. The main limitation in power scaling of famous neodymium doped lasers such as Nd:YVO4 is the thermal lensing effect. Thermal lensing degrades the output beam quality and in extreme cases can result in crystal fracture. One potential solution to this problem is to reduce the induced heat load inside the gain media by decreasing the quantum defect. This was demonstrated successfully for the Nd:YVO4 laser by pumping the laser at a long wavelength of 914 nm instead of the traditional pumping at 808 nm wavelength. Among the Nd-doped crystals operating in the near infrared range, the crystal of yttrium lithium fluoride (Nd:YLF) is another interesting gain medium as it has the benefits of natural birefringence (can generate naturally polarized laser beam), negative dn/dT (reduces thermal effects) and long upper level lifetime (in favor of Q-switched operation). In this work we used a long wavelength pumping approach and for the first time examined the performance of a continuous-wave Nd:YLF laser at 1047 nm under 908 nm diode pumping. This pumping wavelength reduced the quantum defect by 50% as compared to the conventional 808 nm pumping. The laser produced an output power of 850 mW at 1047 nm with excellent beam quality and 625 mW at 1053 nm. The slope efficiency was ~73.9% and 46% for 1047 and 1053 nm, respectively. Therefore, a considerable power scaling is possible for Nd:YLF crystals owing to the strongly reduced quantum defect and, hence, thermal lensing.

Our group has previously developed a PET insert for simultaneous PET/MRI imaging. The insert consists of silicon photomultipliers (SiPMs) with a resistor-based charge division multiplexing readout circuit. Some limitations include a 2.5ns coincidence time resolution (CTR), a relatively long signal duration of >1.5us, and a 1.3us paralyzable dead time. This thesis focuses on characterizing these limitations and demonstrating a second-generation detector module for improved timing and count rate performance. First, optical coupling optimization using acrylic polymer tapes versus conventional silicone optical grease was investigated. Second, CTR and signal duration was reduced by using an enhanced readout board equipped with three new SiPM-type detectors. Last, dead time of the system was reduced by minimizing the sampling number of the OpenPET acquisition system. Future work includes design modification to accommodate the first-generation scintillator footprint and potentially to adapt the OpenPET acquisition system to read in SiPM `fast' outputs.

For several biomedical nonlinear applications mega-watt (MW) peak power lasers working in the near-infrared (NIR) wavelength range are desirable. A cost-effective diode-pumped sub-100-fs solid-state laser oscillator with MW peak power in the NIR wavelength range is not readily available on the commercial market. This thesis presents the successful development of several high power continuous wave (CW) and intense short pulse laser designs. Two laser gain media, namely Yb:KY(WO4)2 (Yb:KYW) and Yb: CaGdAlO4 (Yb:CALGO), were studied in this thesis. These solid-state laser crystals were end-pumped with high power diode laser at ~980 nm. Initially, the continuous wave operation of Yb:KYW with 9W of output power at 1045 nm was demonstrated. The developed Yb:KYW had the highest slope efficiency of 77.9% when compared to all other diode-pumped Yb:KYW lasers. At the same time the developed Yb:CALGO laser was capable of delivering tunable multi-watt output power in the wavelength range of approximately 1020 nm to 1070 nm. Based on these results two intense short pulse lasers were designed and developed in this thesis. The first one was a sub-50-fs Kerr-lens and saturable absorber (KLAS) mode-locked Yb:CALGO laser oscillator with a repetition rate of 42.3 MHz. The highest peak power achieved for 45-fs pulses directly from the oscillator was 1.7 MW. The shortest generated pulses were 38-fs with 187 kW of peak power. The second laser was a sub-100-fs Kerr-lens mode-locked (KLM) Yb:CALGO laser with a low repetition rate of 10.2 MHz. The oscillator produced 650 mW of average output power with pulse duration of 66 fs. It also generated 1 W of average power with pulse duration of 72 fs. This corresponds to pulse energy of 64 nJ with a peak power of 0.97 MW and 98 nJ with the peak power of 1.36 MW, respectively. Some of the nonlinear applications of the high intense laser pulses were studied in the final section. Phase-matching conditions of three periodically poled crystals (PPKTP

Alexandrite crystal (Cr-ion doped chrysoberyl, Cr3+: BeAl2O4) is an attractive gain medium for producing ultrashort laser pulses. Alexandrite properties are similar to those of the Ti:sapphire crystal, which is the most widely used crystal for creating ultrashort pulses. Therefore, Alexandrite can be a good candidate for development of ultra-short pulse lasers. To date, the generation of femtosecond pulses from an Alexandrite laser has not been reported. The primary aim of this research was to create an ultrashort pulse Alexandrite laser. In the first stage of this research, a continuous- wave Alexandrite laser was designed, built and optimized to provide maximum output power. Also, its laser beam quality and wavelength tuning range using a single plate birefringent filter was measured. In addition, the basic behavior of the laser to determine its thermal lensing was investigated. Furthermore, a dual-wavelength operation using several single plate birefringent filters was demonstrated for the first time. In the second stage of this research, ultrashort pulses of 420 fs and 380 fs duration from a quantum-dot saturable absorber mode-locked Alexandrite laser were obtained for the first time. Finally, a femtosecond Kerr-lens mode-locked Alexandrite laser that produced 170 fs long pulses was created for the first time. These results can lead to the development of efficient ultrafast Alexandrite oscillators and amplifiers that can replace widely used inefficient and costly Ti:sapphire laser systems.

With the development of electrical apparatus in more-electric aircraft (MEA), demand for higher electric power is increasing rapidly. In turn, this requires a higher voltage level in the power generation system of aircraft which increases the electric stress on the insulation systems. At higher voltages, the insulation systems of more-electric aircraft are prone to partial discharge (PDs) initiation under the operating condition. The objective of this thesis is to perform a comprehensive study on developing diagnostic methods for the insulation condition monitoring and PD source identification. An algorithm is developed based on the combination of wavelet and energy techniques to detect the PD pulses from the measured noisy PD signals. In addition, based on the statistical distributions of PD pulse waveform characteristics, a classification and separation algorithm is developed for the identification of multi-source PDs using kernel support vector machine (KSVM) as the classifier. The experimental results show that the proposed algorithms show a high performance and accuracy for PD source detection and recognition.

Alexandrite crystal (Cr-ion doped chrysoberyl, Cr3+: BeAl2O4) is an attractive gain medium for producing ultrashort laser pulses. Alexandrite properties are similar to those of the Ti:sapphire crystal, which is the most widely used crystal for creating ultrashort pulses. Therefore, Alexandrite can be a good candidate for development of ultra-short pulse lasers. To date, the generation of femtosecond pulses from an Alexandrite laser has not been reported. The primary aim of this research was to create an ultrashort pulse Alexandrite laser. In the first stage of this research, a continuous- wave Alexandrite laser was designed, built and optimized to provide maximum output power. Also, its laser beam quality and wavelength tuning range using a single plate birefringent filter was measured. In addition, the basic behavior of the laser to determine its thermal lensing was investigated. Furthermore, a dual-wavelength operation using several single plate birefringent filters was demonstrated for the first time. In the second stage of this research, ultrashort pulses of 420 fs and 380 fs duration from a quantum-dot saturable absorber mode-locked Alexandrite laser were obtained for the first time. Finally, a femtosecond Kerr-lens mode-locked Alexandrite laser that produced 170 fs long pulses was created for the first time. These results can lead to the development of efficient ultrafast Alexandrite oscillators and amplifiers that can replace widely used inefficient and costly Ti:sapphire laser systems.

The main obstacle in power scaling of the well-known Nd-doped lasers such as Nd:YVO4 is the thermal lensing effect. One of the proposed solutions to effectively alleviate this problem was based on the reduction of heating within the laser crystal. This was extensively investigated with the Nd:YVO4 crystal by pumping the laser at 914 nm instead of the standard pumping at 808 nm wavelength. In context of high power applications, the crystal of Nd:GdVO4 is an interesting alternative to the Nd:YVO4 as it offers the benefits of good spectral features (similar to Nd:YVO4) and much higher thermal conductivity. However, there is only one proof-of-principle work on continuous-wave (CW) Nd:GdVO4 laser using this pumping approach in which an output power of 3.35 W was reported. The full power scaling potential of the Nd:GdVO4 laser crystal to produce high output power has not been demonstrated to date. In this PhD thesis, I addressed this issue and investigated the high power operation of Nd:GdVO4 lasers under a new pumping wavelength of 912 nm. First, the thermal lensing behaviour of a 1063 nm Nd:GdVO4 was studied, both experimentally and by finite element analysis (FEA) method. The thermal lensing strength in Nd:GdVO4 laser under 912 nm pumping was significantly reduced when compared to the Nd:GdVO4 laser with 808 nm pumping or even Nd:YVO4 laser with 914 nm pumping. The next step of this research was focused on high power operation of Nd:GdVO4 lasers where we achieved 19.8 W of output power at 1063 nm. As a side work in the CW regime of operation, the possibility of discrete wavelength tuning and dual-wavelength operation of the Nd:GdVO4 laser were examined by using an intracavity birefringent filter. Discrete wavelength operation at four different wavelengths was demonstrated. Furthermore, for the first time we were able to demonstrate a dual-wavelength operation of the Nd:GdVO4 laser as a 1063 and 1071 nm wavelength pair. The last aspect of this PhD thesis was concentrate

Our group has previously developed a PET insert for simultaneous PET/MRI imaging. The insert consists of silicon photomultipliers (SiPMs) with a resistor-based charge division multiplexing readout circuit. Some limitations include a 2.5ns coincidence time resolution (CTR), a relatively long signal duration of >1.5us, and a 1.3us paralyzable dead time. This thesis focuses on characterizing these limitations and demonstrating a second-generation detector module for improved timing and count rate performance. First, optical coupling optimization using acrylic polymer tapes versus conventional silicone optical grease was investigated. Second, CTR and signal duration was reduced by using an enhanced readout board equipped with three new SiPM-type detectors. Last, dead time of the system was reduced by minimizing the sampling number of the OpenPET acquisition system. Future work includes design modification to accommodate the first-generation scintillator footprint and potentially to adapt the OpenPET acquisition system to read in SiPM `fast' outputs.

Alexandrite crystal (Cr-ion doped chrysoberyl, Cr3+: BeAl2O4) is an attractive gain medium for producing ultrashort laser pulses. Alexandrite properties are similar to those of the Ti:sapphire crystal, which is the most widely used crystal for creating ultrashort pulses. Therefore, Alexandrite can be a good candidate for development of ultra-short pulse lasers. To date, the generation of femtosecond pulses from an Alexandrite laser has not been reported. The primary aim of this research was to create an ultrashort pulse Alexandrite laser. In the first stage of this research, a continuous- wave Alexandrite laser was designed, built and optimized to provide maximum output power. Also, its laser beam quality and wavelength tuning range using a single plate birefringent filter was measured. In addition, the basic behavior of the laser to determine its thermal lensing was investigated. Furthermore, a dual-wavelength operation using several single plate birefringent filters was demonstrated for the first time. In the second stage of this research, ultrashort pulses of 420 fs and 380 fs duration from a quantum-dot saturable absorber mode-locked Alexandrite laser were obtained for the first time. Finally, a femtosecond Kerr-lens mode-locked Alexandrite laser that produced 170 fs long pulses was created for the first time. These results can lead to the development of efficient ultrafast Alexandrite oscillators and amplifiers that can replace widely used inefficient and costly Ti:sapphire laser systems.

For several biomedical nonlinear applications mega-watt (MW) peak power lasers working in the near-infrared (NIR) wavelength range are desirable. A cost-effective diode-pumped sub-100-fs solid-state laser oscillator with MW peak power in the NIR wavelength range is not readily available on the commercial market. This thesis presents the successful development of several high power continuous wave (CW) and intense short pulse laser designs. Two laser gain media, namely Yb:KY(WO4)2 (Yb:KYW) and Yb: CaGdAlO4 (Yb:CALGO), were studied in this thesis. These solid-state laser crystals were end-pumped with high power diode laser at ~980 nm. Initially, the continuous wave operation of Yb:KYW with 9W of output power at 1045 nm was demonstrated. The developed Yb:KYW had the highest slope efficiency of 77.9% when compared to all other diode-pumped Yb:KYW lasers. At the same time the developed Yb:CALGO laser was capable of delivering tunable multi-watt output power in the wavelength range of approximately 1020 nm to 1070 nm. Based on these results two intense short pulse lasers were designed and developed in this thesis. The first one was a sub-50-fs Kerr-lens and saturable absorber (KLAS) mode-locked Yb:CALGO laser oscillator with a repetition rate of 42.3 MHz. The highest peak power achieved for 45-fs pulses directly from the oscillator was 1.7 MW. The shortest generated pulses were 38-fs with 187 kW of peak power. The second laser was a sub-100-fs Kerr-lens mode-locked (KLM) Yb:CALGO laser with a low repetition rate of 10.2 MHz. The oscillator produced 650 mW of average output power with pulse duration of 66 fs. It also generated 1 W of average power with pulse duration of 72 fs. This corresponds to pulse energy of 64 nJ with a peak power of 0.97 MW and 98 nJ with the peak power of 1.36 MW, respectively. Some of the nonlinear applications of the high intense laser pulses were studied in the final section. Phase-matching conditions of three periodically poled crystals (PPKTP

With the development of electrical apparatus in more-electric aircraft (MEA), demand for higher electric power is increasing rapidly. In turn, this requires a higher voltage level in the power generation system of aircraft which increases the electric stress on the insulation systems. At higher voltages, the insulation systems of more-electric aircraft are prone to partial discharge (PDs) initiation under the operating condition. The objective of this thesis is to perform a comprehensive study on developing diagnostic methods for the insulation condition monitoring and PD source identification. An algorithm is developed based on the combination of wavelet and energy techniques to detect the PD pulses from the measured noisy PD signals. In addition, based on the statistical distributions of PD pulse waveform characteristics, a classification and separation algorithm is developed for the identification of multi-source PDs using kernel support vector machine (KSVM) as the classifier. The experimental results show that the proposed algorithms show a high performance and accuracy for PD source detection and recognition.

Alexandrite crystal (Cr-ion doped chrysoberyl, Cr3+: BeAl2O4) is an attractive gain medium for producing ultrashort laser pulses. Alexandrite properties are similar to those of the Ti:sapphire crystal, which is the most widely used crystal for creating ultrashort pulses. Therefore, Alexandrite can be a good candidate for development of ultra-short pulse lasers. To date, the generation of femtosecond pulses from an Alexandrite laser has not been reported. The primary aim of this research was to create an ultrashort pulse Alexandrite laser. In the first stage of this research, a continuous- wave Alexandrite laser was designed, built and optimized to provide maximum output power. Also, its laser beam quality and wavelength tuning range using a single plate birefringent filter was measured. In addition, the basic behavior of the laser to determine its thermal lensing was investigated. Furthermore, a dual-wavelength operation using several single plate birefringent filters was demonstrated for the first time. In the second stage of this research, ultrashort pulses of 420 fs and 380 fs duration from a quantum-dot saturable absorber mode-locked Alexandrite laser were obtained for the first time. Finally, a femtosecond Kerr-lens mode-locked Alexandrite laser that produced 170 fs long pulses was created for the first time. These results can lead to the development of efficient ultrafast Alexandrite oscillators and amplifiers that can replace widely used inefficient and costly Ti:sapphire laser systems.

This thesis is focused on the development of a novel pendulum-based planar near-field antenna measurement system that is compact, cost-effective, and accurate. This system is capable of characterizing the far-field pattern of an antenna under test (AUT) which is one of the main attribute for evaluating the performance of an AUT. This is accomplished by measuring the electric field component arising from the AUT on a planar surface that is in close proximity to the AUT (i.e., field measurements in the near-field zone of the AUT), and then using mathematical techniques to find the far-field pattern of the AUT. The design of the proposed system is inspired by the motion of free swinging pendulum enabled by the gravitational force. With this natural motion, it is possible to greatly reduce the positioning error of the proposed near-field system and the cost at the same time.

Today, the development of a simple, compact and cost-effective laser source which is capable of generating powerful pulses is of importance for a variety of optical applications. The commercially available Yb:KGW laser crystal is a good candidate for high power regime due to its high thermal conductivity and for ultrashort pulse generation because of its broad gain bandwidth. First, the generation of watt-level sub-100 fs pulse generation was realized by using a quantum-dot semiconductor saturable absorber mirror (QD-SESAM) in a dual-action with the Kerr lensing effect. The high power laser was one of the highest among sub-100 fs diode-pumped bulk Yb-doped lasers. The laser also delivered the shortest pulses from monoclinic double tungstate crystals and also the most powerful in the sub-60 fs regime. Next, a watt-level pure Kerr-lens mode-locked (KLM) laser was realized for the first time with Yb:KGW laser crystal pumped by a multimode fibre-coupled laser diode.

The laser has been used in many areas of science and technology. At the same time there are different types of lasers and conical refraction (CR) laser is one of them. Recently, there has been a strong interest in conical refraction lasers and their applications. CR lasers have the potential applications in areas like optical trapping, free space communication, super-resolution microscopy, quantum computing, cryptography, polarization demultiplexing and multiplexing, polarimetry, mode conversion and so on. The biaxial crystal of Neodymium-doped potassium gadolinium tungstate (Nd:KGW) has been used to produce a CR laser output with in-band pumping. Unfortunately, the thermal conductivity of this crystal is relatively low which limits the high-power operation even for in-band pumping at longer wavelength which decreases the quantum defect and leads to a significant reduction of thermal load in the crystal. This thesis addressed this aspect by proposing a “passive” CR laser scheme. In this work, we demonstrated two types of CR lasers, an active CR laser and a passive CR laser. In active CR laser the functions of laser gain medium and CR element are performed by the same crystal. In passive CR laser these functions are separated: the laser radiation is produced by one crystal and CR is done by the other. The active CR Nd:KGW laser produced and output power of 1.15 W with 32% of slope efficiency and 25.6% optical to optical efficiency. The characteristic hollow ring of the CR laser mode was not observed because the incident laser beam diameter was very large compared to the CR ring diameter supported by the crystal. For passive CR laser, Nd:KGW crystal was placed inside the Nd:YVO laser cavity and a CR ring has been seen with the proper alignment. The CR operation was confirmed by comparing the laser beam shape with a reference He-Ne laser beam passed through the Nd:KGW crystal in a separate experiment. For 10.8 W of absorbed pump power the maximum obtained CR laser outp

This work proposed to study Neodymium-doped laser crystals as an alternative for ultrashort pulse generation with medium output power level and high efficiency. The first section of this thesis focused on the thermal effect which is the main limitation in power scaling. The results showed that the thermal lensing effect is significantly reduced with in-band pumping at 914 nm. Aside from thermal lens effect investigation, discrete wavelength tuning and dual-wavelength operations were demonstrated with intracavity birefringent plates. Mode locking operations with SESAM as saturable absorber was demonstrated under 914 nm pump wavelength for the first time with the highest efficiency to date. The output in mode-locked regime was stable and self-starting with 16 ps pulse duration which can be extended to adjacent emission lines at 1073 nm and 1085 nm. Finally, two important candidates for low quantum defect pumping, Nd:CALYO and Nd:SYSO, were identified and tested for the first time.

Optical Coherence Tomography (OCT) has established itself as an important imaging technology for biomedical and industrial applications. In this thesis, we describe the design and implementation of a novel Full-Field OCT optical module that is specifically designed to fit inside an Olympus IX73 inverted microscope. We describe the design, components, and implementation of this novel optical module in detail. The resulting FF-OCT setup (microscope and OCT optical module) can be used as either a Time-Domain system or a Fourier-Domain (swept-source) system, without the need for considerable changes to the OCT optical module. However, we used our FF-OCT setup to implement a Time-Domain FF-OCT system. We describe our FF-OCT system’s data acquisition process and Graphical User Interface (GUI) in detail, and we present imaging results obtained for samples comprised of stacks of glass coverslips.

Distributed optical fiber sensing (DOFS) is a set of technologies that are characterized by their ability to use optical fiber as the sensing mechanism. This allows for measurements to be obtained from any spatial location along the fiber. It can be used in environments where wired, or wireless technologies cannot always be deployed, such as in high temperature environments. It also allows for sensing over long distances without the need for batteries or power to remote locations. Although there are papers describing the development of DOFS systems for various applications, often the literature does not provide an adequate description of the physics of light scattering required to understand the technology in these systems. A review of light scattering with respect to this technology is provided. Additionally, the development of a simulator for a coherent phase-OTDR is described. This simulator provides a means of comparing theory with experiment for DOFS applications.

This thesis is focused on the development of a novel pendulum-based planar near-field antenna measurement system that is compact, cost-effective, and accurate. This system is capable of characterizing the far-field pattern of an antenna under test (AUT) which is one of the main attribute for evaluating the performance of an AUT. This is accomplished by measuring the electric field component arising from the AUT on a planar surface that is in close proximity to the AUT (i.e., field measurements in the near-field zone of the AUT), and then using mathematical techniques to find the far-field pattern of the AUT. The design of the proposed system is inspired by the motion of free swinging pendulum enabled by the gravitational force. With this natural motion, it is possible to greatly reduce the positioning error of the proposed near-field system and the cost at the same time.

Today, the development of a simple, compact and cost-effective laser source which is capable of generating powerful pulses is of importance for a variety of optical applications. The commercially available Yb:KGW laser crystal is a good candidate for high power regime due to its high thermal conductivity and for ultrashort pulse generation because of its broad gain bandwidth. First, the generation of watt-level sub-100 fs pulse generation was realized by using a quantum-dot semiconductor saturable absorber mirror (QD-SESAM) in a dual-action with the Kerr lensing effect. The high power laser was one of the highest among sub-100 fs diode-pumped bulk Yb-doped lasers. The laser also delivered the shortest pulses from monoclinic double tungstate crystals and also the most powerful in the sub-60 fs regime. Next, a watt-level pure Kerr-lens mode-locked (KLM) laser was realized for the first time with Yb:KGW laser crystal pumped by a multimode fibre-coupled laser diode.

The laser has been used in many areas of science and technology. At the same time there are different types of lasers and conical refraction (CR) laser is one of them. Recently, there has been a strong interest in conical refraction lasers and their applications. CR lasers have the potential applications in areas like optical trapping, free space communication, super-resolution microscopy, quantum computing, cryptography, polarization demultiplexing and multiplexing, polarimetry, mode conversion and so on. The biaxial crystal of Neodymium-doped potassium gadolinium tungstate (Nd:KGW) has been used to produce a CR laser output with in-band pumping. Unfortunately, the thermal conductivity of this crystal is relatively low which limits the high-power operation even for in-band pumping at longer wavelength which decreases the quantum defect and leads to a significant reduction of thermal load in the crystal. This thesis addressed this aspect by proposing a “passive” CR laser scheme. In this work, we demonstrated two types of CR lasers, an active CR laser and a passive CR laser. In active CR laser the functions of laser gain medium and CR element are performed by the same crystal. In passive CR laser these functions are separated: the laser radiation is produced by one crystal and CR is done by the other. The active CR Nd:KGW laser produced and output power of 1.15 W with 32% of slope efficiency and 25.6% optical to optical efficiency. The characteristic hollow ring of the CR laser mode was not observed because the incident laser beam diameter was very large compared to the CR ring diameter supported by the crystal. For passive CR laser, Nd:KGW crystal was placed inside the Nd:YVO laser cavity and a CR ring has been seen with the proper alignment. The CR operation was confirmed by comparing the laser beam shape with a reference He-Ne laser beam passed through the Nd:KGW crystal in a separate experiment. For 10.8 W of absorbed pump power the maximum obtained CR laser outp

This work proposed to study Neodymium-doped laser crystals as an alternative for ultrashort pulse generation with medium output power level and high efficiency. The first section of this thesis focused on the thermal effect which is the main limitation in power scaling. The results showed that the thermal lensing effect is significantly reduced with in-band pumping at 914 nm. Aside from thermal lens effect investigation, discrete wavelength tuning and dual-wavelength operations were demonstrated with intracavity birefringent plates. Mode locking operations with SESAM as saturable absorber was demonstrated under 914 nm pump wavelength for the first time with the highest efficiency to date. The output in mode-locked regime was stable and self-starting with 16 ps pulse duration which can be extended to adjacent emission lines at 1073 nm and 1085 nm. Finally, two important candidates for low quantum defect pumping, Nd:CALYO and Nd:SYSO, were identified and tested for the first time.

Optical Coherence Tomography (OCT) has established itself as an important imaging technology for biomedical and industrial applications. In this thesis, we describe the design and implementation of a novel Full-Field OCT optical module that is specifically designed to fit inside an Olympus IX73 inverted microscope. We describe the design, components, and implementation of this novel optical module in detail. The resulting FF-OCT setup (microscope and OCT optical module) can be used as either a Time-Domain system or a Fourier-Domain (swept-source) system, without the need for considerable changes to the OCT optical module. However, we used our FF-OCT setup to implement a Time-Domain FF-OCT system. We describe our FF-OCT system’s data acquisition process and Graphical User Interface (GUI) in detail, and we present imaging results obtained for samples comprised of stacks of glass coverslips.

Distributed optical fiber sensing (DOFS) is a set of technologies that are characterized by their ability to use optical fiber as the sensing mechanism. This allows for measurements to be obtained from any spatial location along the fiber. It can be used in environments where wired, or wireless technologies cannot always be deployed, such as in high temperature environments. It also allows for sensing over long distances without the need for batteries or power to remote locations. Although there are papers describing the development of DOFS systems for various applications, often the literature does not provide an adequate description of the physics of light scattering required to understand the technology in these systems. A review of light scattering with respect to this technology is provided. Additionally, the development of a simulator for a coherent phase-OTDR is described. This simulator provides a means of comparing theory with experiment for DOFS applications.

Solid-state lasers are capable of providing versatile output characteristics with greater flexibility compared to other popular laser systems. Lasing action has been achieved in many hundreds of solid-state media, but Nd-ion doped gain media are widely used to reach high power levels with short pulses. In this work, commercially available Nd:KGW crystal served as a gain medium to achieve pulsed operation at 1067 nm. This laser crystal offers large stimulated emission crosssection and gain bandwidth which facilitates generation of high peak power pulses in the picosecond regime. The KGW crystal is monoclinic and biaxial in structure, and anisotropic in its optical and thermal properties. Due to poor thermal conductivity, this crystal can be operated within a limited power range before crystal fracture takes place. To reduce the amount of heat deposited in the gain media, we introduced a new pumping wavelength of 910 nm which reduces the quantum defect by more than 45%. Continuous-wave laser operation was optimized to operate in mode-locked regime. In order to achieve short light pulses from the continuous-wave laser, one of the end mirrors was replaced by a semiconductor saturable absorber mirror (SESAM) to generate 2.4 ps pulses at a repetition rate of 83.8 MHz. An average output power of 87 mW was obtained at lasing wavelength of 1067 nm and the beam was nearly diffraction limited with M^2 < 1.18. The peak power of the generated pulses was 427 W and energy of each pulse was >1 nJ. Pumping the crystal at longer wavelength (910 nm) reduced the thermal lensing of the crystal by half when compared to conventional pumping at shorter wavelength (808 nm). To the best of our knowledge, this is the first time passive mode-locking of a Nd:KGW laser was explored using the pump wavelength at 910 nm.

Solid-state lasers are capable of providing versatile output characteristics with greater flexibility compared to other popular laser systems. Lasing action has been achieved in many hundreds of solid-state media, but Nd-ion doped gain media are widely used to reach high power levels with short pulses. In this work, commercially available Nd:KGW crystal served as a gain medium to achieve pulsed operation at 1067 nm. This laser crystal offers large stimulated emission crosssection and gain bandwidth which facilitates generation of high peak power pulses in the picosecond regime. The KGW crystal is monoclinic and biaxial in structure, and anisotropic in its optical and thermal properties. Due to poor thermal conductivity, this crystal can be operated within a limited power range before crystal fracture takes place. To reduce the amount of heat deposited in the gain media, we introduced a new pumping wavelength of 910 nm which reduces the quantum defect by more than 45%. Continuous-wave laser operation was optimized to operate in mode-locked regime. In order to achieve short light pulses from the continuous-wave laser, one of the end mirrors was replaced by a semiconductor saturable absorber mirror (SESAM) to generate 2.4 ps pulses at a repetition rate of 83.8 MHz. An average output power of 87 mW was obtained at lasing wavelength of 1067 nm and the beam was nearly diffraction limited with M^2 < 1.18. The peak power of the generated pulses was 427 W and energy of each pulse was >1 nJ. Pumping the crystal at longer wavelength (910 nm) reduced the thermal lensing of the crystal by half when compared to conventional pumping at shorter wavelength (808 nm). To the best of our knowledge, this is the first time passive mode-locking of a Nd:KGW laser was explored using the pump wavelength at 910 nm.

Cardiovascular disease is one of the leading causes of death in Canada. Atherosclerosis is considered the primary cause for cardiovascular disease. Optical coherence tomography (OCT) provides a means to minimally invasive imaging and assessment of textural features of atherosclerotic plaque. However, detecting atherosclerotic plaque by visual inspection from Optical Coherence Tomography (OCT) images is usually difficult. Therefore we developed unsupervised segmentation algorithms to automatically detect atherosclerosis plaque from OCT images. We used three different clustering methods to identify atherosclerotic plaque automatically from OCT images. Our method involves data preprocessing of raw OCT images, feature selection and texture feature extraction using the Spatial Gray Level Dependence Matrix method (SGLDM), and the application of three different clustering techniques: K-means, Fuzzy C-means and Gustafson-Kessel algorithms to segment the plaque regions from OCT images and to map the cluster regions (background, vascular tissue, OCT degraded signal region and Atherosclerosis plaque) from the feature-space back to the original preprocessed OCT image. We validated our results by comparing our segmented OCT images with actual photographic images of vascular tissue with plaque.

The development of the Francium Trapping Facility at TRIUMF, Canada and progress towards an atomic parity violation measurement in francium are underway. Francium (Z = 87) is the heaviest alkali. Its simple atomic structure and large number of nucleons make it an attractive system for weak interaction studies. For this reason, atomic parity violation in francium is an active area of study, and recent years have seen significant progress towards that end. Laser trapping of francium at Triumf has only recently been achieved, and several useful physics measurements for the future atomic parity violation experiment have been performed. The future measurement is of the highly forbidden 7S - 8S optical transition amplitude, which is suppressed by ~ 10^10 compared to an allowed transition amplitude. This will be achieved by interference with an allowed Stark transition, similar to the 6S - 7S optical atomic parity violation measurement in cesium. The commissioning of the two-chamber trapping apparatus as well as the development of the electric field plates for the Stark interference will be reported on. The physics measurements include the photoionization cross-section from the 7P_3/2 states, and isotope shifts of the D1 line. The cross-section must be known to evaluate a potential atom loss mechanism from the 506 nm light of the 7S - 8S excitation, negatively impacting the trapped population. Atomic theory calculations, which are required for the extraction of the weak coupling constants from the atomic measurement, may be benchmarked against these isotope shifts, allowing theorists to refine their techniques for the more sensitive evaluations.

Cardiovascular disease is one of the leading causes of death in Canada. Atherosclerosis is considered the primary cause for cardiovascular disease. Optical coherence tomography (OCT) provides a means to minimally invasive imaging and assessment of textural features of atherosclerotic plaque. However, detecting atherosclerotic plaque by visual inspection from Optical Coherence Tomography (OCT) images is usually difficult. Therefore we developed unsupervised segmentation algorithms to automatically detect atherosclerosis plaque from OCT images. We used three different clustering methods to identify atherosclerotic plaque automatically from OCT images. Our method involves data preprocessing of raw OCT images, feature selection and texture feature extraction using the Spatial Gray Level Dependence Matrix method (SGLDM), and the application of three different clustering techniques: K-means, Fuzzy C-means and Gustafson-Kessel algorithms to segment the plaque regions from OCT images and to map the cluster regions (background, vascular tissue, OCT degraded signal region and Atherosclerosis plaque) from the feature-space back to the original preprocessed OCT image. We validated our results by comparing our segmented OCT images with actual photographic images of vascular tissue with plaque.