Sampling of diode laser spectra by a confocal etalon fringe pattern

This paper presents an original method of IR diode laser spectra sampling, where the sampling is defined by the fringe pattern of a confocal etalon. The laser wave number is scanned between two peaks of the Airy type function and is temporarily locked to each peak, allowing integration of the spectroscopic data on another optoelectronic channel. This method is well adapted to broad absorption line studies, provided the line can afford the relatively large sample spacing (0.01 cm(-1)). A monitoring experiment for both pressure and HBr concentration in halogen bulbs is presented to show an example of the method's use.