Compact, Temperature-Tuned OFDR Laser

About this technology

Overview

Fiber optic sensing systems (FOSS) have advantages over conventional sensors including lighter weight, smaller size, improved reliability, and higher accuracy. To date, wavelength division multiplexing (WDM) has perhaps been the most popular fiber optic sensing method. Drawbacks of WDM exist, however, including the importance of fiber Bragg grating (FBG) sensor locations, need for each sensor to have a unique wavelength, and limited number of sensors that can occupy any one data channel (~10). As a result, NASA has focused on OFDR, an alternative FBG interrogation technique based on laser interferometry. OFDR provides advantages over WDM, most notably higher spatial density (up to 1000 FBGs can be multiplexed into a single fiber), and reduced cost per sensor. During development of an OFDR-based FOSS system, cost and performance-based limitations of traditional excitation sources led NASA to develop a novel, wavelength-swept, solid-state laser tailored to this application.