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Heart rate measurement is a basic and essential for daily health monitoring. A heart rate monitoring system is a personal monitoring device that allows one to measure heart rate in real-time. If someone wants to record the data or use it to trigger events, there is a need to turn that mechanical pulsing action into an electrical signal and this can be done only through heart rate measuring system. The pulse rate helps to find out if the heart is pumping enough blood to the body and also helps to find the cause of various symptoms such as an irregular or rapid heartbeat, dizziness, fainting, chest pain or difficulty in breathing. More than million people are at high risk of having heart related diseases. It would be helpful if there was a way for these people to check the heart rate by sitting at home. In this paper focus have been made on realizing a portable, comfortable and low cost solution for long-term domestic heart rate monitoring. There are various methods or technologies to measure the domestic heart rate. We have mainly focused on IoT-based, polymer-based pressure sensors, optical sensors, plastic optical fiber sensor, smart phones, MEMS based piezoelectric pressure sensor. The most effective method will be considered as an efficient way of detecting the heart rate.

Heart rate measurement is a basic and essential for daily health monitoring. A heart rate monitoring system is a personal monitoring device that allows one to measure heart rate in real-time. If someone wants to record the data or use it to trigger events, there is a need to turn that mechanical pulsing action into an electrical signal and this can be done only through heart rate measuring system. The pulse rate helps to find out if the heart is pumping enough blood to the body and also helps to find the cause of various symptoms such as an irregular or rapid heartbeat, dizziness, fainting, chest pain or difficulty in breathing. More than million people are at high risk of having heart related diseases. It would be helpful if there was a way for these people to check the heart rate by sitting at home. In this paper focus have been made on realizing a portable, comfortable and low cost solution for long-term domestic heart rate monitoring. There are various methods or technologies to measure the domestic heart rate. We have mainly focused on IoT-based, polymer-based pressure sensors, optical sensors, plastic optical fiber sensor, smart phones, MEMS based piezoelectric pressure sensor. The most effective method will be considered as an efficient way of detecting the heart rate.

Heart rate measurement is a basic and essential for daily health monitoring. A heart rate monitoring system is a personal monitoring device that allows one to measure heart rate in real-time. If someone wants to record the data or use it to trigger events, there is a need to turn that mechanical pulsing action into an electrical signal and this can be done only through heart rate measuring system. The pulse rate helps to find out if the heart is pumping enough blood to the body and also helps to find the cause of various symptoms such as an irregular or rapid heartbeat, dizziness, fainting, chest pain or difficulty in breathing. More than million people are at high risk of having heart related diseases. It would be helpful if there was a way for these people to check the heart rate by sitting at home. In this paper focus have been made on realizing a portable, comfortable and low cost solution for long-term domestic heart rate monitoring. There are various methods or technologies to measure the domestic heart rate. We have mainly focused on IoT-based, polymer-based pressure sensors, optical sensors, plastic optical fiber sensor, smart phones, MEMS based piezoelectric pressure sensor. The most effective method will be considered as an efficient way of detecting the heart rate.

Heart rate measurement is a basic and essential for daily health monitoring. A heart rate monitoring system is a personal monitoring device that allows one to measure heart rate in real-time. If someone wants to record the data or use it to trigger events, there is a need to turn that mechanical pulsing action into an electrical signal and this can be done only through heart rate measuring system. The pulse rate helps to find out if the heart is pumping enough blood to the body and also helps to find the cause of various symptoms such as an irregular or rapid heartbeat, dizziness, fainting, chest pain or difficulty in breathing. More than million people are at high risk of having heart related diseases. It would be helpful if there was a way for these people to check the heart rate by sitting at home. In this paper focus have been made on realizing a portable, comfortable and low cost solution for long-term domestic heart rate monitoring. There are various methods or technologies to measure the domestic heart rate. We have mainly focused on IoT-based, polymer-based pressure sensors, optical sensors, plastic optical fiber sensor, smart phones, MEMS based piezoelectric pressure sensor. The most effective method will be considered as an efficient way of detecting the heart rate.

Liquid level measurement in microfluidics is challenging, where a sensor with ultra-high sensitivity but miniature in nature is demanded. In this paper, we propose for the first time a microsized fiber sensor structure in both diameter and length for microfluidics applications, which is capable of sub-micrometer scale liquid level measurement. The sensor is simply fabricated by fusion splicing a short section of a hollow core fiber (HCF) between two singlemode fibers (SMFs). HCFs with different air core diameters (10 µm, 20 µm, 30 µm) were investigated and it is found that for a given length of HCF stronger resonant dips were excited in transmission for the HCF with a smaller air core diameter. Thus the HCF structure with an air core diameter of 10 µm (HCF-10) was used for demonstration of high sensitivity liquid level measurement in microfluidics. Simultaneous excitation of both Anti-Resonant Reflecting Optical Waveguide (ARROW) guiding mechanism and Mach-Zehnder interferometer (MZI) in transmission is demonstrated in such an HCF-10 structure when HCF-10 is longer than the critical length. A maximum sensitivity of 0.042 dB/µm (corresponding to a calculated liquid level resolution of ~0.23 µm) was experimentally achieved with an HCF-10 length of ~867 µm, which is three times higher than that of the previous reported to date of the most sensitive fiber optic liquid level sensors based on intensity modulation. In addition, the proposed sensor shows good repeatability of measurement and a very low cross sensitivity to changes in the surrounding refractive index., source:https://www.sciencedirect.com/science/article/pii/S0924424721005999

Heart rate measurement is a basic and essential for daily health monitoring. A heart rate monitoring system is a personal monitoring device that allows one to measure heart rate in real-time. If someone wants to record the data or use it to trigger events, there is a need to turn that mechanical pulsing action into an electrical signal and this can be done only through heart rate measuring system. The pulse rate helps to find out if the heart is pumping enough blood to the body and also helps to find the cause of various symptoms such as an irregular or rapid heartbeat, dizziness, fainting, chest pain or difficulty in breathing. More than million people are at high risk of having heart related diseases. It would be helpful if there was a way for these people to check the heart rate by sitting at home. In this paper focus have been made on realizing a portable, comfortable and low cost solution for long-term domestic heart rate monitoring. There are various methods or technologies to measure the domestic heart rate. We have mainly focused on IoT-based, polymer-based pressure sensors, optical sensors, plastic optical fiber sensor, smart phones, MEMS based piezoelectric pressure sensor. The most effective method will be considered as an efficient way of detecting the heart rate.

Certain applications of fiber sensors (e.g. avionics, oil industry) imply extreme operating conditions spurring the development of hermetic all-fiber devices. We present a hermetic all-fiber phase modulator based on Joule heating in a carbon-coated fiber., QC 20190523

We proposed a composite microfiber using silica capillary and Ag microparticles, and demonstrated its optical sensing characteristics by changing the refractive index of surrounding environment using different concentrations of NaCl solution. Either the diameter or doping density of Ag microparticles contributes to the sensitivity change. The experimental results reveal that the diameter uniformity and distribution of Ag microparticles exerted impact on the sensing performance. The highest sensitivity of −7246 dB/RIU has been experimentally demonstrated in this work. The selectivity of this composite microfiber sensor will be explored by decorating its surface with some enzyme or other sensitive materials.

The main topic of this thesis work is photosensitivity and photo-structuring of optical fibers and bulk glass. Although research in the field of photosensitivity in glass and optical fibers has been ongoing for more than three decades, the underlying mechanisms are still not well understood. The objective was to gain a better understanding of the photo-response by studying photosensitivity from a thermodynamic perspective, as opposed to established research focusing on point defects and structural changes, and strain and stress in optical fibers. Optical fibers was mainly used for experimental studies for two reasons; first, photosensitivity in fibers is more pronounced and more elusive compared to its bulk counterpart, and secondly, fibers provide a simplified structure to study as they experimentally can be seen as one-dimensional.Initially, ablation experiments on bulk glass were performed using picosecond infrared pulses. With a design cross section of 40x40 μm, straight channels were fabricated on the top (facing incident light) and bottom side of the sample and the resulting geometries were analyzed. The results show a higher sensitivity to experimental parameters for bottom side ablation which was ascribed to material incubation effects. Moreover, on the top side, the resulting geometry has a V-shape, independent of experimental parameters, related to the numerical aperture of the focusing lens, which was ascribed to shadowing effects.After this work, the focus shifted towards optical fibers, UV-induced fiber Bragg gratings (FBGs) and thermal processing with conventional oven and with a CO2 laser as a source of radiant heat.First, a system for CO2 laser heating of optical fibers was constructed. For measuring the temperature of the processed fibers, a special type of FBG with high temperature stability, referred to as "Chemical Composition Grating" (CCG) was used. A thorough characterization and temperature calibration was performed and the results show the t, Huvudtemana i denna avhandling är fotokänslighet och fotostrukturering av optiska fibrer och bulk glas. Trots att forskning inom fotokänslighet i glas och optiska fibrer har pågått under mer än tre decennier är de bakomliggande mekanismerna ännu inte klarlagda. Syftet var att få en bättre förståelse för fotoresponsen genom att studera fotokäsligheten ur ett termodynamiskt perspektiv, i motsats till etablerad forskning med fokus på punktdefekter och strukturförändringar, samt mekaniska spännings effekter i optiska fibrer. Optiska fibrer användes för flertalet av de experimentella studierna av två skäl; för det första är fotokänsligheten i fibrer större och dessutom vet man mindre om bakomliggande mekanismer jämfört med motsvarande bulk glas, och för det andra kan fibrer vara enklare att studera eftersom de experimentellt kan ses som en endimensionell struktur.Inledningsvis utfördes ablaherings experiment på bulk glas med en infraröd laser med pikosekund pulser. Raka kanaler med ett designtvärsnitt på 40x40 μm tillverkades på ovansidan (mot infallande ljus) och bottensidan av provet och de resulterande geometrierna analyserades. Resultaten visar en högre känslighet för variationer i experimentella parametrar vid ablahering på undersidan vilket kan förklaras av inkubations effekter i materialet. Dessutom är den resulterande geometrin på ovansidan V-formad, oavsett experimentella parametrar, vilket kunde relateras till den numeriska aperturen hos den fokuserande linsen, vilket förklaras av skuggningseffekter.Efter detta arbete flyttades fokus mot optiska fibrer, UV inducerade fiber Bragg gitter (FBG), och termisk bearbetning med konventionell ugn samt även med en CO2-laser som källa för strålningsvärme.Först konstruerades ett system för CO2-laservärmning av fibrer. För mätning av temperaturen hos bearbetade fibrer användes en speciell sorts FBG med hög temperaturstabilitet, kallade ”Chemical Composition Gratings” (CCG). En grundlig karaktärisering och temperaturkalibrer, QC 20150924

The main topic of this thesis work is photosensitivity and photo-structuring of optical fibers and bulk glass. Although research in the field of photosensitivity in glass and optical fibers has been ongoing for more than three decades, the underlying mechanisms are still not well understood. The objective was to gain a better understanding of the photo-response by studying photosensitivity from a thermodynamic perspective, as opposed to established research focusing on point defects and structural changes, and strain and stress in optical fibers. Optical fibers was mainly used for experimental studies for two reasons; first, photosensitivity in fibers is more pronounced and more elusive compared to its bulk counterpart, and secondly, fibers provide a simplified structure to study as they experimentally can be seen as one-dimensional.Initially, ablation experiments on bulk glass were performed using picosecond infrared pulses. With a design cross section of 40x40 μm, straight channels were fabricated on the top (facing incident light) and bottom side of the sample and the resulting geometries were analyzed. The results show a higher sensitivity to experimental parameters for bottom side ablation which was ascribed to material incubation effects. Moreover, on the top side, the resulting geometry has a V-shape, independent of experimental parameters, related to the numerical aperture of the focusing lens, which was ascribed to shadowing effects.After this work, the focus shifted towards optical fibers, UV-induced fiber Bragg gratings (FBGs) and thermal processing with conventional oven and with a CO2 laser as a source of radiant heat.First, a system for CO2 laser heating of optical fibers was constructed. For measuring the temperature of the processed fibers, a special type of FBG with high temperature stability, referred to as "Chemical Composition Grating" (CCG) was used. A thorough characterization and temperature calibration was performed and the results show the t, Huvudtemana i denna avhandling är fotokänslighet och fotostrukturering av optiska fibrer och bulk glas. Trots att forskning inom fotokänslighet i glas och optiska fibrer har pågått under mer än tre decennier är de bakomliggande mekanismerna ännu inte klarlagda. Syftet var att få en bättre förståelse för fotoresponsen genom att studera fotokäsligheten ur ett termodynamiskt perspektiv, i motsats till etablerad forskning med fokus på punktdefekter och strukturförändringar, samt mekaniska spännings effekter i optiska fibrer. Optiska fibrer användes för flertalet av de experimentella studierna av två skäl; för det första är fotokänsligheten i fibrer större och dessutom vet man mindre om bakomliggande mekanismer jämfört med motsvarande bulk glas, och för det andra kan fibrer vara enklare att studera eftersom de experimentellt kan ses som en endimensionell struktur.Inledningsvis utfördes ablaherings experiment på bulk glas med en infraröd laser med pikosekund pulser. Raka kanaler med ett designtvärsnitt på 40x40 μm tillverkades på ovansidan (mot infallande ljus) och bottensidan av provet och de resulterande geometrierna analyserades. Resultaten visar en högre känslighet för variationer i experimentella parametrar vid ablahering på undersidan vilket kan förklaras av inkubations effekter i materialet. Dessutom är den resulterande geometrin på ovansidan V-formad, oavsett experimentella parametrar, vilket kunde relateras till den numeriska aperturen hos den fokuserande linsen, vilket förklaras av skuggningseffekter.Efter detta arbete flyttades fokus mot optiska fibrer, UV inducerade fiber Bragg gitter (FBG), och termisk bearbetning med konventionell ugn samt även med en CO2-laser som källa för strålningsvärme.Först konstruerades ett system för CO2-laservärmning av fibrer. För mätning av temperaturen hos bearbetade fibrer användes en speciell sorts FBG med hög temperaturstabilitet, kallade ”Chemical Composition Gratings” (CCG). En grundlig karaktärisering och temperaturkalibrer, QC 20150924

The main topic of this thesis work is photosensitivity and photo-structuring of optical fibers and bulk glass. Although research in the field of photosensitivity in glass and optical fibers has been ongoing for more than three decades, the underlying mechanisms are still not well understood. The objective was to gain a better understanding of the photo-response by studying photosensitivity from a thermodynamic perspective, as opposed to established research focusing on point defects and structural changes, and strain and stress in optical fibers. Optical fibers was mainly used for experimental studies for two reasons; first, photosensitivity in fibers is more pronounced and more elusive compared to its bulk counterpart, and secondly, fibers provide a simplified structure to study as they experimentally can be seen as one-dimensional.Initially, ablation experiments on bulk glass were performed using picosecond infrared pulses. With a design cross section of 40x40 μm, straight channels were fabricated on the top (facing incident light) and bottom side of the sample and the resulting geometries were analyzed. The results show a higher sensitivity to experimental parameters for bottom side ablation which was ascribed to material incubation effects. Moreover, on the top side, the resulting geometry has a V-shape, independent of experimental parameters, related to the numerical aperture of the focusing lens, which was ascribed to shadowing effects.After this work, the focus shifted towards optical fibers, UV-induced fiber Bragg gratings (FBGs) and thermal processing with conventional oven and with a CO2 laser as a source of radiant heat.First, a system for CO2 laser heating of optical fibers was constructed. For measuring the temperature of the processed fibers, a special type of FBG with high temperature stability, referred to as "Chemical Composition Grating" (CCG) was used. A thorough characterization and temperature calibration was performed and the results show the t, Huvudtemana i denna avhandling är fotokänslighet och fotostrukturering av optiska fibrer och bulk glas. Trots att forskning inom fotokänslighet i glas och optiska fibrer har pågått under mer än tre decennier är de bakomliggande mekanismerna ännu inte klarlagda. Syftet var att få en bättre förståelse för fotoresponsen genom att studera fotokäsligheten ur ett termodynamiskt perspektiv, i motsats till etablerad forskning med fokus på punktdefekter och strukturförändringar, samt mekaniska spännings effekter i optiska fibrer. Optiska fibrer användes för flertalet av de experimentella studierna av två skäl; för det första är fotokänsligheten i fibrer större och dessutom vet man mindre om bakomliggande mekanismer jämfört med motsvarande bulk glas, och för det andra kan fibrer vara enklare att studera eftersom de experimentellt kan ses som en endimensionell struktur.Inledningsvis utfördes ablaherings experiment på bulk glas med en infraröd laser med pikosekund pulser. Raka kanaler med ett designtvärsnitt på 40x40 μm tillverkades på ovansidan (mot infallande ljus) och bottensidan av provet och de resulterande geometrierna analyserades. Resultaten visar en högre känslighet för variationer i experimentella parametrar vid ablahering på undersidan vilket kan förklaras av inkubations effekter i materialet. Dessutom är den resulterande geometrin på ovansidan V-formad, oavsett experimentella parametrar, vilket kunde relateras till den numeriska aperturen hos den fokuserande linsen, vilket förklaras av skuggningseffekter.Efter detta arbete flyttades fokus mot optiska fibrer, UV inducerade fiber Bragg gitter (FBG), och termisk bearbetning med konventionell ugn samt även med en CO2-laser som källa för strålningsvärme.Först konstruerades ett system för CO2-laservärmning av fibrer. För mätning av temperaturen hos bearbetade fibrer användes en speciell sorts FBG med hög temperaturstabilitet, kallade ”Chemical Composition Gratings” (CCG). En grundlig karaktärisering och temperaturkalibrer, QC 20150924

The advent of new optical fibre technologies in recent years have revolutionized the telecommunications and sensing field. In particular the rapid development of microstructured fiber, also known as photonic crystal fiber (PCF), brings about remarkable features such as air guided mechanism, unique geometric structure and single material fibre structure that could overcome many limitations intrinsic to conventional standard optical fibers.This thesis reports my research and original results from the development and application of microstuctured fibre as fiber humidity sensors. My work covers the design and fabrication of the PCF-based sensors, development of experimental systems with related data generation and acquisition capabilities, novel sensing schemes and techniques as well as proof of concept experiments. I proposed and experimentally demonstrated several novel fibre humidity sensor schemes which do not require coating of any hygroscopic or sensitive film while most of previous reported fiber humidity sensors need the hygroscopic films to sense humidity. I also proposed and demonstrated a microstructured optical fibre based humidity sensor for respiration monitoring for possible application of PCF-based fiber sensors in the bio-medical engineering field.

We numerically study and compare the performance limitations imposed by accumulated noise and nonlinear phase difference in various configurations of amplified fiber optic gyroscopes in which amplification is provided by stimulated Raman scattering, with a focus on ultralong and random distributed feedback Raman fiber lasers. We show that, even in the presence of pump power and signal instabilities, some of the proposed configurations have the potential to allow the use of up to 5 times longer spool lengths, with a corresponding 5-fold increase in sensitivity. The results could have direct application to the improvement of the detection of seismic rotational events. © 2013 Elsevier Ltd.

This effort provides the ability to characterize curved surface velocity range and maxima. It also affords the opportunity to place the probe inside clay or gel backing material to measure backface deformation. The fiber sensor probe can be used in a sacrificial manner in explosive events to characterize surface velocity up to the time the probe is destroyed, providing a low-cost alternative to x-ray and high-speed camera systems for measuring material velocities., The original document contains color images.

A surface plasmon resonance biochemical sensor based on a tilted fiber Bragg grating imprinted in a single mode fiber core is demonstrated. A 30-50. nm thick gold coating on the cladding of the fiber provides the support for surface plasmon waves whose interaction with attached biomolecules is monitored at near infrared wavelengths near 1550. nm. The transmission spectrum of the sensor provides a fine comb of narrowband resonances that overlap with the broader absorption of the surface plasmon and thus provide a unique tool to measure small shifts of the plasmon with high accuracy. The attachment on the gold surfaces of aptamers with specific affinities for proteins provides the required target-analyte system and is shown to be functional in the framework of our sensing device. The implementation of the sensor either as a stand-alone device or as part of a multi-sensor platform is also described.

A transversal-load sensor based on the local pressure-induced refractive index change in a chirped fiber Bragg grating (CFBG) is proposed. The local pressure induced refractive index change in the touch point can generate a main transmission peak and several subpeaks on the long wavelength side of the reflection band of the CFBG. The difference of the wavelength shifts for the main transmission peak and the first subpeak is used to measure transversal-load with temperature compensation capability., QC 20100525

We describe a highly sensitive refractive index sensor based on a twin-core coupler in an all-solid photonic bandgap guiding optical fiber. A single hole acts as a microfluidic channel for the analyte, which modifies the coupling between the cores, and avoids the need for selective filling. By operating in the bandgap guiding regime the proposed sensor is capable of measuring refractive indices around that of water, and because the analyte varies the coupling coefficient (i.e., instead of phase matching condition) the device is capable of both high sensitivity and a relatively large dynamic range.

We describe a highly sensitive refractive index sensor based on a twin-core coupler in an all-solid photonic bandgap guiding optical fiber. A single hole acts as a microfluidic channel for the analyte, which modifies the coupling between the cores, and avoids the need for selective filling. By operating in the bandgap guiding regime the proposed sensor is capable of measuring refractive indices around that of water, and because the analyte varies the coupling coefficient (i.e., instead of phase matching condition) the device is capable of both high sensitivity and a relatively large dynamic range.

A high-resolution strain/temperature sensing system based on a fiber Bragg grating-Fabry-Perot cavity (FBG-FPC) and a wavelength-swept single-longitudinal-mode laser diode (modulated by a sawtooth signal) is proposed. The high-finesse (similar to 627) FBG-FPC formed by two uniform FBGs of high reflectivity (similar to 99.5%) is used both as a strain/temperature sensor and a FPC with ultranarrow (similar to 0.12 pm) transmission bands. Using a photodetector to detect the transmissive light of the laser diode through the FBG-FPC, wavelength demodulation is achieved by mapping wavelength measurement to time measurement. Both strain sensing and temperature sensing with a resolution of 0.11 mu epsilon and 0.014 degrees C, respectively, have been demonstrated., QC 20100525

We have theoretically investigated twin-core all-solid photonic bandgap fibers (PBGFs) for evanescent wave sensing of refractive index within one single microfluidic analyte channel centered between the two cores. The sensor can achieve ultrahigh sensitivity by detecting the change in transmission. We find novel features in the sensing characteristics: the sensitivity is higher at the short wavelength edge of a bandgap than at the long wavelength edge, the effective index of the odd supermode (nodd) is more sensitive to ambient refractive index change compared with that of the even supermode (neven).

A tightly bending loss technique is developed for application in biomedical WDM fiber sensors. In this paper, we present the measurement and comparison of bending sensor in 1.3 micronmeter and 1.55 micronmeter wavelength region, respectively. A two - wavelength measurement setup is built for bending loss testing. Various wrapping method and turns are invested for studying the bending loss for broadband biomedical sensing system. We found that as the bending loss increases, the oblique angle of wrapping become large. These research results is helpful for multi-channel multi-array fiber optic biomedical sensor systems., Proceedings of SPIE, v4082, 26-27 Jul 2000, p265-274. This article is from ADA398019 Optical Sensing, Imaging and Manipulation for Biological and Biomedical Applications Held in Taipei, Taiwan on 26-27 July 2000. Proceedings