Abstract

In the interest of increasing the sensitivity of laser spectroscopy, investigators are turning to techniques utilizing high frequency modulation [1,2] and polarization [3] to lower the detection threshold. In the case of high-resolution-high-frequency modulation laser spectroscopy, beating between the modulation side bands allows one to obtain formidable sensitivity [1]. For investigators using high frequency modulation with pump-probe picosecond spectroscopy [2], the side bands produced are negligibly displaced relative to the laser spectral bandwidth; thus the carrier frequency (or sums and differences of carrier frequencies on different laser beams [4,5]) are detected directly.

© 1984 Optical Society of America