Interferometric system controlled by virtual instrumentation for differential thermal analysis

Abstract

This work describes the implementation of an optical fiber interferometric system for differential thermal analysis. The system is based on a white light Mach-Zehnder configuration, with serrodyne phase modulation, to interrogate two identical fiber Bragg gratings (FBG) in a differential scheme. Operation and signal processing with low cost digital instrumentation developed in Labview environment enabled FBG temperature measurement with a ±0.012ºC resolution nearly matching the performance of standard hardware. Preliminary results were obtained, where mixed samples of acetone and methanol could be successfully identified, indicating the suitability of the system for high accuracy differential thermal analysis using low cost instrumentation.

Temperature independent refractive index measurement using white light interferometry

“…White Light Interferometry (WLI) has been used for remote measurement of diverse parameters such as strain, temperature and pressure [7][8][9]. This technique uses low coherence optical sources providing absolute measurement at high resolution and the ability of multiplexing sensors onto a single optical fiber using coherence multiplexing [10,11] In this work an interferometric readout system, controlled with virtual instrumentation, is described where a Mach-Zehnder white light system is used to interrogate two similar non-adiabatic fiber tapers in a differential arrangement.…”