Sampled grating DBR laser as a spectroscopic source in multigas detection at 1.52-1.57 mu m

The first application is reported of multigas sensing using a widely tuneab le sampled grating DBR laser with a tuning range 1520 less than or equal to lambda less than or equal to 1570 nm. The laser diode consists of four ind ependently biased sections, two sampled gratings, a phase section and a gai n section. Setting the laser emission wavelength within its broad tuning ra nge is achieved by tuning the front and back grating mirrors. Three gases H 2S, C2H2 and CO2 with absorption features within the 30 nm tuning range of the device were targeted and successfully detected. In addition, minimum de tection limits were estimated using wavelength modulation spectroscopy. Ini tial results demonstrate the value of this device as a light source in abso rption spectroscopy based multigas detection systems.