Harsh environment temperature and strain sensor using tunable VCSEL and multiple fiber bragg gratings

Harsh environment applications, such as aerospace and oil extraction, require small, lightweight and robust sensors. The new temperature and strain sensor system presented here consists of a tunable VCSEL, optical circulator, fiber with Bragg gratings at different wavelengths, and pin detectors. It has broad dynamic range, high sensitivity, low weight and a very simple detection scheme. When compared to other fiber Bragg grating approaches, it consumes low power, occupies less space and has its intelligence in the electrical domain, coupled to the optical devices.

I. Introduction

Harsh environments are originally characterized by extreme operation under one or several of the following stress conditions: mechanical, thermal or chemical. More and more, an additional characteristic of such environments has become their remote or difficult-to-access location.