Diode Laser-Based Evanescent Wave Fiber Optic Sensor

Physical Sciences Inc. (PSI) proposes to develop and demonstrate an ultra-sensitive, compact, and versatile evanescent wave, fiber optic sensor for detecting chlorinated hydrocarbons in air, water or headspace matrices. The sensor will be built around the emerging technology in room temperature near-IR diode lasers, ultra-sensitive absorption detection technology, and state-of-the-art fiber coating technology which is hydrophobic and reversibly enriches C-c1 compounds for detection in the evanescent mode. In this Phase I program we will demonstrate detection of two common solvents, 1, 2-dichloroethene (DCE) and 1,1,1 trichloroethene (TCE). Detection of DCE and TCE will be conducted using two different light sources in the near-IR, a diode laser source and a tunable white light source. The two systems will be evaluated for detection sensitivity, cost, power comsumption, size, lifetime, stability, and overall robustness for field applications. Included in the Phase I proposal is a demonstration at the Armstrong Laboratory Environics Directorate. During the Phase II program PSI will deliver an evanescent wave fiber optic sensor for the detection of chlorinated hydrocarbons. Our goal for the Phase I program is to begin the development of a prototype integrated evanescent wave fiber optic sensor, spectrometer, and data collection and analysis system.