SINGLE-BEAM DIODE-LASER TECHNIQUE FOR OPTICAL PATH-LENGTH MEASUREMENTS

摘要

A simple single-beam technique employing radio-frequency modulation of a tunable diode laser with homodyne demodulation is demonstrated as a means of measuring optical path lengths. This technique offers a straightforward method for determining path lengths traversed through optical multipass cells or performing optical range-finding over short (i.e., tens of meters) standoff distances. The radiofrequency phase-sensitive nature of the technique permits narrow-band detection and high signal-to-noise ratios, even when range-finding measurements are made with range resolutions of 1 m. This compares favorably with traditional short-pulse, wide-bandwidth optical range finders. (C) 1996 Optical Society of America [References: 14]