Optical Sensors Essay

990 Words 4 Pages
In today’s world sensors especially optical sensors have many emerging applications beginning from the medical diagnostics to detect the pollution in the environment. Because of these wide range of applications the challenges faced to design, proper functioning and maintenance of an optical sensor requires immense knowledge of optical, material, and environmental properties that could affect sensor performance in all aspects. The wavelength range of the laser, interactions between the signal and the target, the effect of the environment on the transmission of the signal, methods used to amplify the optical signal, and materials which are used to focus on and collect the optical signal are all important aspects of optical sensors. This report …show more content…
Introduction

In general an optical sensor basically is like any other device which could converts light rays(laser beams) into electronic signals, into a form ie readable. Fiber optic sensors have numerous advantages over other conventional electronic sensors. Some important advantages are as below
• Ability to integrate different structure.
• Their inability to conduct electric current.
• Highly resistive to electromagnetic interference.
• Lightweight with high sensitivity.
• Multiplexing capability.

1.1 Optical fiber: Basics

An optical fiber is composed of three parts the core: dielectric material (glass), light propagation the cladding: lesser Refractive index of core(glass/plastic) stops loss of light from core scattering loss at the surface of the core the coating: protect an optical fiber from physical damage.

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1.2 Fiber optic sensor principle

The block diagram an optical fiber sensor system is shown above. It consists of an optical source (Laser), optical fiber, sensing element, an optical detector and processing electronics such as oscilloscope. This can be classified under three
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Among all of those Rayleigh scattering is studied because of its peculiar characteristics which giving us the advantage of real sensing mechanisms. When scattering happens in fiber, some of the scattered light which will be radiating in all different directions will be captured by the guiding mode of the fiber itself and will again back propagates to the fiber input while the remaining scattered light will be dissipated into the surrounding environment. This backscattered light is the signal detected whose strength varies from case to case but in general is

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