Abstract

Nonlinear frequency conversion of infrared and red laser diode emission offers the possibility of a compact, lightweight, low-cost, low-complexity, electrically efficient source of tunable, narrow band UV radiation. Such sources are required for spectroscopy, detection of atmospheric gases, photolithography, reprographics, medical cytometers and optical data storage. In particular, tunable UV radiation in the 200-320 nm spectral range is used for detection of many small molecules and radicals¹ of interest in studies of combustion and atmospheric chemistry, e.g. NO, OH, CIO, SO2, H2CO. This spectroscopically important region is inaccessible however, by SHG using presently available diode lasers. To overcome this limitation, we demonstrate the first use of higher order conversion process to generate deep UV at 215 nm and 286 nm by frequency quadrupling and tripling the 860 nm emission of a modelocked laser containing a GaAlAs tapered amplifier gain element.²

© 1995 Optical Society of America