Design of Reflective Intensity Modulated Fiber-Optic Sensor Based on TracePro and Taguchi Method

Abstract: Compare with traditional way of numerical simulation by establishing the mathematical model through geometry optic, we design a TracePro model to analyze the sensing process of reflective intensitymodulated fiber optic sensor base on ray tracing. This type of sensor has advantages over other fiber optic sensor, including simple structure, flexible design, reliable perform, low cost etc. In this paper, to design the reflective intensity modulated fiber optic sensor with concave reflected surface, TracePro software is used for modeling, TP modeling results are consistent with the existing conclusions show that the method is reasonably effectively, can improve the design efficiency. Meanwhile the Taguchi method is used to optimize coupling efficiency of receiving fiber in fiber optic displacement sensor design. Through optimizing three controllable factors the optimization configuration of A1B1C1 combinations is gain, presents a viable solution for the design of this sensor type

Performance analysis of a noncontact plastic fiber optical fiber displacement sensor with compensation of target reflectivity

peer-reviewedAn inexpensive fiber-based noncontact distance sensor specific for monitoring short-range displacements in micromachining applications is presented. To keep the overall costs low, the sensor uses plastic optical fibers and an intensiometric approach based on the received light intensity after the reflection from the target whose displacement has to be measured. A suitable target reflectivity compensation technique is implemented to mitigate the effects due to target surface nonuniformity or ageing.The performances of the sensor are first evaluated for different fiber configurations and target reflectivity profiles and positions using a numerical method based on Monte Carlo simulations. Then, experimental validations on a configuration designed to work up to 1.5mm have been conducted. The results have confirmed the validity of the proposed sensor architecture, which demonstrated excellent compensation capabilities, with errors below 0.04mm in the (0-1)mm range regardless the color and misalignment of the target

Statistical Analysis On Impact Of Temperature To Fiber Bragg Grating Sensor Performance

This paper studied the feasibility of statistical approach to aid in the development of the fiber Bragg grating (FBG) temperature monitoring system using analysis of variance approach. Upon completion, the sensitivity of the sensor measured for DI water and palm oil is 0.00149 dBm/ ⁰C and 0.0273 dBm/ ⁰C, respectively. In terms of the wavelength shift, the sensitivity of 13.1 pm/ ⁰C and 25.29 pm/ ⁰C were achieved for DI water and palm oil, respectively. The coefficients of determination (R2) for temperature variations relationships were 0.986 for DI water and 0.9806 for palm oil. This study showed the great potential of statistical approach in predicting the sensor device performance

OPTICAL AND OPTOMECHANICAL RESONATORS AND THEIR APPLICATIONS IN COMMUNICATION AND SENSING

The radiation pressure of the large circulating optical power inside micro-scale high quality factor Whispering-Gallery mode micoresonators couples the mechanical deformation of the resonator structure to the optical resonance. This coupling results in damping or amplification of the corresponding mechanical modes. Self-sustained mechanical oscillation takes place when the optomechanical gain becomes larger than mechanical loss. In this dissertation, several applications of optomechanical oscillator (OMO) in communication and sensing are proposed and explored using silica microtoroid resonator. First we investigate the spectrum of the OMO and define weak\u27 and \u27strong\u27 harmonic generation regimes based on two distinct spectral behaviors. In weak harmonic regime, an analytical method is proposed to optimize the spectral behavior of an OMO for RF-photonic communication systems. In the strong harmonic regime, we show that OMO spectrum can be used in a read-out system for resonant optical sensing applications. Next, we explore optomechanical RF mixing and its application in RF-photonics. We study optomechanical RF mixing using coupled differential equations as well as a semi-analytical model that simplifies the calculation of mixed frequency components. Furthermore, optomechanical down-conversion of various waveforms and audio signal from an RF carrier are demonstrated. Here for the first time we show that an OMO can function as a high-resolution mass sensor based on optomechanical oscillation frequency shift. In an OMO based mass sensor, optical power simultaneously servers as an efficient actuator and a sensitive probe for monitoring optomechanical oscillation frequency variations. The narrow linewidth of optomechanical oscillation and the small effective mass of the corresponding mechanical mode result in sub-pg mass sensitivity. We analyze the performance of microtoroid OMO mass sensor and evaluate its ultimate detection limit. The outcomes of our study enable combination of resonant optical sensing with optomechanical sensing in a single device. This so-called \u27dual-mode\u27 sensing can be a powerful technique for measuring the properties (mass, density and refractive index) of micro/nano-particles and molecules. To boost the optical sensitivity of the dual-mode sensor, we also demonstrate a dynamic sensing method where the resonant photonic sensitivity is improved by over 50 times through thermally induced line narrowing

Review of Fiber Optic Displacement Sensors

Displacement Measurements Are of Significant Importance in a Variety of Critical Scientific and Engineering Fields, Such as Gravitational Wave Detection, Geophysical Research, and Manufacturing Industries. Due to the Inherent Advantages Such as Compactness, High Sensitivity, and Immunity to Electromagnetic Interference, in Recent Years, Fiber Optic Sensors Have Been Widely Used in an Expansive Range of Sensing Applications, Ranging from Infrastructural Health Monitoring to Chemical and Biological Sensing. of Particular Interest Here, Fiber Optic Displacement Sensors Have Gained Wide Interest and Have Evolved from Basic Intensity Modulation-Based Configurations to More Advanced Structures, Such as Fiber Bragg Grating (FBG)-Based and Interferometric Configurations. This Article Reviews Specifically the Advanced Fiber Optic Displacement Sensing Techniques that Have Been Developed in the Past Two Decades. Details Regarding the Working Principle, Sensor Design, and Performance Measures of FBG-Based, Interferometers-Based (Including the Fabry-Perot Interferometer, the Michelson Interferometer, and the Multimode Interferometer), Microwave Photonics-Based, and Surface Plasmon Resonance-Based Fiber Optic Displacement Sensors Are Given. Challenges and Perspectives on Future Research in the Development of Practical and High-Temperature Tolerant Displacement Sensors Are Also Discussed

Macrobend optical sensing for pose measurement in soft robot arms

This paper introduces a pose-sensing system for soft robot arms integrating a set of macrobend stretch sensors. The macrobend sensory design in this study consists of optical fibres and is based on the notion that bending an optical fibre modulates the intensity of the light transmitted through the fibre. This sensing method is capable of measuring bending, elongation and compression in soft continuum robots and is also applicable to wearable sensing technologies, e.g. pose sensing in the wrist joint of a human hand. In our arrangement, applied to a cylindrical soft robot arm, the optical fibres for macrobend sensing originate from the base, extend to the tip of the arm, and then loop back to the base. The connectors that link the fibres to the necessary opto-electronics are all placed at the base of the arm, resulting in a simplified overall design. The ability of this custom macrobend stretch sensor to flexibly adapt its configuration allows preserving the inherent softness and compliance of the robot which it is installed on. The macrobend sensing system is immune to electrical noise and magnetic fields, is safe (because no electricity is needed at the sensing site), and is suitable for modular implementation in multi-link soft continuum robotic arms. The measurable light outputs of the proposed stretch sensor vary due to bend-induced light attenuation (macrobend loss), which is a function of the fibre bend radius as well as the number of repeated turns. The experimental study conducted as part of this research revealed that the chosen bend radius has a far greater impact on the measured light intensity values than the number of turns (if greater than five). Taking into account that the bend radius is the only significantly influencing design parameter, the macrobend stretch sensors were developed to create a practical solution to the pose sensing in soft continuum robot arms. Henceforward, the proposed sensing design was benchmarked against an electromagnetic tracking system (NDI Aurora) for validation

Sensors for ceramic components in advanced propulsion systems: Summary of literature survey and concept analysis, task 3 report

The results of a literature survey and concept analysis related to sensing techniques for measuring of surface temperature, strain, and heat flux for (non-specific) ceramic materials exposed to elevated temperatures (to 2200 K) are summarized. Concepts capable of functioning in a gas turbine hot section environment are favored but others are reviewed also. Recommendation are made for sensor development in each of the three areas

Advanced adaptive compensation system for free-space optical communications

Massive amounts of information are created daily in commercial fields like earth observation, that must be downloaded to earth ground stations in the short time of a satellite pass. Today, much of the collected information must be dropped due to lack of bandwidth, and laser downlinks can offer tenths of gigabits throughput solving this bottleneck limitation. In a down-link scenario, the performance of laser satellite communications is limited due to atmospheric turbulence, which causes fluctuations in the intensity and the phase of the received signal leading to an increase in bit error probability. In principle, a single-aperture phase-compensated receiver, based on adaptive optics, can overcome atmospheric limitations by adaptive tracking and correction of atmospherically induced aberrations. However, under strong-turbulence situations, the effectiveness of traditional adaptive optics systems is severely compromised. In such scenarios, sensor-less techniques offer robustness, hardware simplicity, and easiness of implementation and integration at a reduced cost, but the state-of-the-art approaches still require too many iterations to perform the correction, exceeding the temporal coherence of the field and thus falling behind the field evolution. This thesis proposes a new iterative AO technique for strong turbulence compensation that reduces the correction time, bridging the limitation of similar systems in lasercom applications. It is based on the standard sensor-less system design, but it additionally uses a short-exposure focal intensity image to accelerate the correction. The technique combines basic principles of Fourier optics, image processing, and quadratic signal optimization to correct the wave-front. This novel approach directly updates the phases of the most intense focal-plane speckles, maximizing the power coupled into a single-mode fiber convexly. Numerical analyses show that this method has a robust and excellent performance under very strong turbulence. Laboratory results confirm that a focal speckle pattern can be used to accelerate the iterative compensation. This technique delivers nearly twofold bandwidth reduction compared with standard methods, and sufficient signal gain and stability to allow high throughput data transmission with nearly error-free performance in emulated satellite downlink scenarios. A property highlight is the in-advance knowledge of the required number of iterations, allowing on-demand management of the loop bandwidth in different turbulent regimes. Besides remaining conceptually and technically simple, it opens a new insight to iterative solutions that may lead to the development of new methods. With further refinement, this technique can surely contribute to making possible the use of iterative solutions in laser communicationsSatélites de observación de la tierra diariamente generan gigantescas cantidades de datos que deben ser enviados a estaciones terrenas. La mayoría de la información recolectada debe desecharse debido al reducido tiempo visible de un satélite en movimiento y el limitado ancho de banda de transmisión. Enlaces ópticos pueden solucionar esta limitación ofreciendo multi-gigabit de ancho de banda. Sin embargo, el desempeño de un downlink laser está limitado por la turbulencia atmosférica, la cual induce variaciones en la intensidad y la fase de la señal recibida incrementando la probabilidad de error en los datos recibidos. En principio, un receptor basado en una apertura simple utilizando óptica adaptativa puede corregir las aberraciones de fase inducidas por la atmósfera, mejorando el canal de transmisión. Sin embargo, la eficiencia de los sistemas de óptica adaptativa tradicionales se ve seriamente reducida en situaciones de turbulencia fuerte. En tales escenarios, técnicas iterativas ofrecen mayor robustez, simplicidad de diseño e implementación, así como también facilidad de integración a un costo reducido. Desafortunadamente, dicha tecnología aún requiere demasiadas iteraciones para corregir la fase distorsionada, excediendo el tiempo de coherencia del frente de onda. Esta tesis propone una nueva técnica iterativa de óptica adaptativa capaz de reducir el tiempo de convergencia en escenarios de turbulencia fuerte. La técnica utiliza el diseño tradicional de los sistemas de corrección iterativos, agregando el uso de una imagen focal de intensidad para acelerar el proceso de corrección del campo distorsionado. En dicha técnica se combinan principios básicos de óptica de Fourier, procesamiento de imagen, y optimización cuadrática de la señal para corregir el frente de onda. De esta forma, la fase de los puntos focales de mayor intensidad (speckles) puede modificarse directamente y con ello maximizar de forma convexa la potencia acoplada en fibra. Los análisis numéricos demuestran robustez y un excelente desempeño en escenarios de turbulencia fuerte. Los resultados de laboratorio confirman que el moteado de intensidad puede utilizarse para acelerar la corrección iterativa. Esta técnica utiliza la mitad del ancho de banda requerido con la técnica tradicional, al mismo tiempo que ofrece suficiente ganancia y estabilidad de la señal para lograr enlaces ópticos con muy baja probabilidad de error. Al mismo tiempo, la técnica propuesta permite conocer con anticipación el número total de iteraciones y posibilita la administración bajo demanda del ancho de banda requerido en diferentes escenarios de turbulencia. Esta tesis ofrece una mirada diferente a los métodos iterativos, posibilitando el desarrollo de nuevos conceptos y contribuyendo al uso de soluciones iterativas en comunicaciones laser por espacio libre.Postprint (published version