Abstract

The method of doing dual-beam single-detector wavelength-modulation spectroscopy originally proposed by Bonfiglioli and Trench is demonstrated experimentally, using a tunable laser. This system monitors both the reference and the sample beams continuously in phase quadrature and measures the derivative and the direct spectra simultaneously. When this system was used in conjunction with an electro-optically tuned cw dye laser, a sensitivity of (1/T) (dT/dλ) = 3 × 10⁻⁶ Å⁻¹ was experimentally achieved for modulation depths from 1 to 50 Å and can be extended down to 0.1 Å. The derivative spectrum corresponding to the extremely weak fifth overtone of the C–H stretching vibration in the electronic ground state of benzene has been observed in a path length as short as 1 cm.

© 1977 Optical Society of America

High-sensitivity infrared heterodyne radiometer using a tunable-diode-laser local oscillator

R. T. Ku and D. L. Spears
Opt. Lett. 1(3) 84-86 (1977)

Stimulated Raman spectroscopy using low-power cw lasers

Adelbert Owyoung and Eric D. Jones
Opt. Lett. 1(5) 152-154 (1977)

High-resolution transient-double-resonance spectroscopy in SF₆

P. F. Moulton, D. M. Larsen, J. N. Walpole, and A. Mooradian
Opt. Lett. 1(2) 51-53 (1977)

Modulated transmission spectroscopy of gaseous chemi-excited Ca and Sr monoxides

D. J. Benard, W. D. Slafer, P. J. Love, and P. H. Lee
Appl. Opt. 16(8) 2108-2115 (1977)

Complete frequency coverage for submillimeter laser spectroscopy with optically pumped CH₃OH, CH₃OD, CD₃OD, and CH₂CF₂

B. L. Bean and S. Perkowitz
Opt. Lett. 1(6) 202-204 (1977)