Development of a narrow-band, tunable, frequency-quadrupled diode laser for UV absorption spectroscopy

A compact, lightweight, low-power-consumption source of tunable, narrow-bandwidth blue and UV radiation is described. In this source, a single-longitudinal-mode diode laser seeds a pulsed, GaAlAs tapered amplifier whose similar to 860-nm output is frequency quadrupled by two stages of single-pass frequency doubling. Performance of the laser system is characterized over a wide range of amplifier duty cycles (0.1-1.0), pulse durations (50 ns-1.0 mu s), peak currents (less than or equal to 14 A), and average currents (less than or equal to 2.0 A). The capabilities and limitations of this source are discussed. We recorded high-resolution, Doppler-limited absorption spectra of nitric oxide and sulfur dioxide near 215 MI; the SO2 spectrum was found to have significantly more structure and higher peak absorption cross sections than previously reported. (C) 1998 Optical Society of America.