Abstract

We report the demonstration of two-tone optical heterodyne spectroscopy with a tunable lead-salt diode laser. Using high-frequency modulation of the diode-laser injection current, we demonstrated a detection-sensitivity limit of 1 × 10⁻⁵ to differential absorption from Doppler-broadened NH₃ lines in the 930-cm⁻¹ region. In our experiment, this limit was set by preamplifier noise and the low quantum efficiency of the photodetector. A substantial increase in sensitivity should be possible by using an improved detector, an improved preamplifier, and higher optical power.

© 1986 Optical Society of America

Two-tone optical heterodyne spectroscopy using buried double heterostructure lead–salt diode lasers

Joel A. Silver and Alan C. Stanton
Appl. Opt. 27(21) 4438-4444 (1988)

High-frequency-modulation spectroscopy with a lead-salt diode laser

Manfred Gehrtz, Wilfried Lenth, Anthony T. Young, and Harold S. Johnston
Opt. Lett. 11(3) 132-134 (1986)

Frequency modulation spectroscopy with lead–salt diode lasers: a comparison of single-tone and two-tone techniques

David E. Cooper and Russell E. Warren
Appl. Opt. 26(17) 3726-3732 (1987)

Two-tone optical heterodyne spectroscopy with diode lasers: theory of line shapes and experimental results

David E. Cooper and Russell E. Warren
J. Opt. Soc. Am. B 4(4) 470-480 (1987)

High-sensitivity FM spectroscopy with a lead-salt diode laser

David E. Cooper and Clinton B. Carlisle
Opt. Lett. 13(9) 719-721 (1988)