Abstract

Fabry-Perot interferometers have been used in many applications for wavelength and spectral measurements. Our objective is to develop and construct a wavemeter to provide laser wavelength centroid measurements of tunable solidstate lasers. Because of the high resolution and prior use in many applications, the classical Fabry-Perot-based wavemeter was chosen. With interferometers, one of the most difficult problems is to maintain thermal stability over ambient temperature excursions. For the wavemeter, a two-stage thermal control has been evaluated. The interferometer is mounted in a thermal-vacuum chamber with fine temperature control. This interferometer system is then enclosed with a second housing with course thermal control. In both cases, the temperature control is above ambient to provide simpler regulation. With the thermal control provided, the other variable is how to mount the Fabry-Perot interferometer to minimize thermally induced mechanical mounting stresses. Several support fixtures were evaluated using a Zeeman stabilized single frequency He-Ne laser as the source and a photodiode array as the detector. The laser is considered a perfect source with any end-to-end interferometer output variations caused by thermal-mechanical mounting stresses. A wide range of end-to-end measurements on a three-finger flexture support provides data to within the stabilization specification of the He-Ne laser.

© 1988 Optical Society of America