A Possible Use of Fiber-Optic Ring Resonator as a Nano-Scale Optical Sensor for Detection of Physical Quantities

Melika E Seraji,Faramarz E Seraji,H Golnabi

doi:10.5923/j.optics.20120205.04

Abstract

This paper presents a proposed fiber-optic ring resonator with a resonance loop made of a conventional single-mode optical fiber as a nano-scale sensor for measurement of physical quantities, such as pressure and temperature. The operational theory of the resonator as an optical sensor is presented, where the effects of characteristic parameters of the resonator on the sensor response is investigated. It is shown that the behavior of sensor response with respect to some particular physical quantities is linear and is capable of detecting measurand variations of the order of 100 nanometers. The proposed sensor is suitable for design of hydrophones used in submarine co mmunicat ions.

Highlights

In the last two decades, fiber-optic ring resonators (FORRs) with fiber and waveguide structures have been used in several applications such as biosensors[1], optical switching[2], add/drop multip lexers[3], laser resonators[4], dispersion compensators[5], optical b istability[6], optical filters[7]
We focus on effects of the FORR parameters such as κ, α, γ, and for the sake of analytical simp licity, we ignore that of laser source
By using a fiber-optic ring resonator, a nano-scale sensor for possible measurements of physical quantities is proposed and its performances are analyzed in terms of characteristic parameters of the ring resonator

Summary

Introduction

In the last two decades, fiber-optic ring resonators (FORRs) with fiber and waveguide structures have been used in several applications such as biosensors[1], optical switching[2], add/drop multip lexers[3], laser resonators[4], dispersion compensators[5], optical b istability[6], optical filters[7]. Performance analyses of FORR under steady and dynamic states are reported, where the resonator responses in terms of characteristic parameters, are investigated[8, 9]. Unlike the other methods[11,12,13], in the present paper, by considering the steady state response of the FORR[9], an analysis of possible use of an FORR as a nano-scale sensor for measure ment of physical quantities such as pressure and temperature is presented. It is shown that if the resonance loop is exposed to a physical quantity of mechanical nature, the output characteristics of the FORR will change linearly in a specified range of wavelengths in response to nano-scale variations of sensing length

Structure of FORR Based Sensor

Response of the Sensor

Effects of FORR Parameters on Sensor Responses

Conclusions