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The development of efficient ultrafast laser sources based on Yb-doped crystals is very important for a variety of optical applications such as nonlinear spectroscopy, nonlinear microscopy, telecommunications etc. A powerful and high beam quality (near diffraction limited: M2~1) pump laser is desirable to mitigate the effect of reabsorption loss that Yb-doped crystals exhibit and realize highly efficient operation in both continuous-wave (CW) and pulsed domains. Unfortunately, there are no commercially available laser diodes that can provide both high beam quality and high output power (>1 W) simultaneously. This thesis presents the development of a powerful and high beam quality pump laser and then utilizes this pump laser to demonstrate the efficient operation of Yb:YAG laser in CW domain and Yb:KGW laser in both the CW and pulsed domains. In the first part of the thesis, a high-power compact CW Nd:YAG laser was built with greatly improved beam quality operating at 946 nm. A maximum output power of 9.98 W with beam quality factor M2 ~ 5 was obtained. I also demonstrated a highly efficient and tunable CW Yb:YAG laser pumped by the developed Nd:YAG laser. The maximum CW output power of 4.37 W was obtained at 1030 nm with optical-to-optical efficiency of 70% with respect to the absorbed pump power. Wavelength tuning of Yb:YAG laser was then explored due to metrological applications such as references for high-resolution spectroscopy or dimensional metrology. The laser produced a continuously tunable operation over 100 nm from 1000 nm to 1100 nm. This is the most tunable laser among bulk crystalline Yb:YAG solid-state lasers. Due to the increasing interest in dual-wavelength (DW) operation for the use as an optical source for terahertz (THz) radiation, this thesis also gave a demonstration of DW Yb:YAG laser operation. This is the first demonstration of DW operation of Yb:YAG laser pumped by a Nd:YAG laser at 946 nm. The latter part of the thesis concentrated on devel

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.

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

High power laser sources of ultrashort pulses (~fs, 10-15 s, femtosecond) have numerous applications in science, medicine, and technology such as spectroscopy, optical coherence tomography, microscopy, laser micromachining and processing of materials (e.g., all smartphone glass screens are cut with ultrashort laser pulses). The generation of ultrashort laser pulses requires a laser gain medium to have a broad emission spectrum. Generation of ultrashort pulses with high average power, on the other hand, also requires the gain medium to have good thermal conductivity. These two requirements (i.e., emission spectrum vs thermal conductivity), unfortunately, are contradictory to each other. Broad emission spectra (>30 nm) are generally observed from materials with disordered structure, i.e., glasses, which have poor thermal conductivity (~1W/m/K). Crystals, on the other hand, have good thermal conductivity (~5-10 W/m/K), but narrow emission spectra (<10 nm). At the same time propagation of intense laser pulses induces strong nonlinear optical effects in laser components (laser crystals, lenses, and even in air, etc.) which all should be minimized to avoid pulse spreading in time. Therefore, generation of ultrashort laser pulses with high average power is not a trivial task not only from the material properties point of view, but also from the way that these pulses are generated and stabilized. A method of generation of ultrashort pulses is called mode locking. Fortunately, a new laser crystal, Yb:CALGO, recently became available which has very good spectroscopic and thermal properties, i.e. 50 nm of bandwidth and 6.9 W/m/K of thermal conductivity. The first stage of the work focused on the continuous-wave (CW) operation of the laser. To enhance the lasing efficiency, the intracavity losses were estimated and made sure that this loss was low. After that, the tuning performance of the laser was evaluated using a 12 mm and 24 mm optimized off-surface axis birefringent filte

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.

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 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