Internally coupled Fabry-Perot interferometer for high precision wavelength control of tunable diode lasers

An internally coupled confocal Fabry-Perot interferometer (FPI) has been developed for both high precision wavelength calibration and stabilization of tunable diode lasers (TDL), which is tunable and thermally stable and works over a large wavelength range (0.6-30 micron) - characteristics that cannot be simultaneously realized with conventional etalons. As part of a versatile wavelength control system the instrument has already considerably improved the quality of the diode laser spectra and will facilitate the use of TDLs in sub-Doppler spectroscopy and as local oscillators in heterodyne radiometers.