For very high precision molecular spectroscopy we use a tunable diode laser which is frequency locked to an internally coupled Fabry-Perot interferometer (icFPI). The spectra are calibrated by means of the interference pattern of an iodine stabilized He-Ne reference laser which is simultaneously coupled into the icFPI. In this paper the exact relation between the diode laser frequency and the He-Ne fringe number is derived and a convenient calibration procedure yielding a frequency accuracy of 5 × 10-5 cm-1 at 10 µm is described.
© 1989 Optical Society of America
Hans-Jörg Clar, R. Schieder, M. Reich, and G. Winnewisser, "High precision frequency calibration of tunable diode lasers stabilized on an internally coupled Fabry-Perot interferometer," Appl. Opt. 28, 1648-1656 (1989)