DESIGN OF A PHOTOWRITTEN CAVITY NEODYMIUM-DOPED FIBER LASER TUNABLE AROUND AN ABSORPTION MOLECULAR LINE

Experiments have shown that it is possible to realize laser cavities p hotowritten within rare-earth-doped silicate fibers. Experimental resu lts on a particular application, namely, the detection of gas traces b y identification of one of the gas's absorption lines, are presented. Experiments on an absorption Line of atmospheric water have been carri ed out to illustrate this purpose. Two lasers have been designed with particular characteristics (spectral linewidths, slope efficiencies, t hresholds). Preliminary experimental results on the detection of an ab sorption line of atmospheric water have been obtained with fiber laser s and optoacoustic detection.