Abstract

Absorption measurements are accomplished by utilizing short pulses of frequency-modulated (FM) light. The absorption is measured by detecting the heterodyne beat signal that occurs when the FM spectrum is distorted by the absorption feature of interest. By using a single short laser pulse it is demonstrated that the beat signal can build up far above the noise level within 1 μsec. The entire absorption structure can be probed by a few laser pulses. Thus pulsed FM spectroscopy permits ultrafast absorption measurements to be made by using an overall light exposure several orders of magnitude smaller than is necessary for traditional absorption techniques.

© 1981 Optical Society of America

Frequency-modulation spectroscopy: a new method for measuring weak absorptions and dispersions

Gary C. Bjorklund
Opt. Lett. 5(1) 15-17 (1980)

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Frequency-modulation Fourier transform spectroscopy: a broadband method for measuring weak absorptions and dispersions

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Pulsed frequency-modulation spectroscopy at 3302 Å

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Frequency-modulation spectroscopy with a pulsed dye laser

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