Demonstration of a rapidly strain tuned Er3+-doped fiber laser for sensitive gas detection

We describe a novel combination of a diode-pumped, wavelength-modulated Er3 +-doped fiber laser light source with a sensitive noise cancellation circui t for detection of acetylene and ammonia. The laser tuning element, a fiber Bragg grating, was mounted in such a way that it could be strained control lably and rapidly, allowing noise cancellation techniques Co be applied to the wavelength-modulated output of the fiber laser. The experimental setup is relatively simple and can be extended to other fiber laser wavelengths f or which semiconductor lasers are net readily available by selection of a d ifferent fi;ber Bragg grating and gain medium. (C) 1999 Optical Society of America.