Abstract

Molecular vibration-rotation lines are interesting for laser-frequency stabilization because of their narrow widths and rich spectra. Now, with tunable diode lasers, it is of interest^1,2 to examine the overtone bands of simple molecules. An important advance was made recently by de Labachelerie, Nakagawa, and Ohtsu,³ who demonstrated the possibility of intracavity saturated absorption spectroscopy on an acetylene-overtone transition at 1.54 μm. Here we push this concept further by using higher overtones to provide many transitions in the visible region while providing potential access to infrared widths in the subkilohertz domain. From these first experiments we report pressure-broadening measurements on the saturated absorption peak in the P (11) line of the vl + 3v3 band of C₂H₂ (acetylene) at 790.7 nm.

© 1995 Optical Society of America