Distributed-feedback dye laser for picosecond ultraviolet and visible spectroscopy

We describe the design and operation of a tunable, picosecond laser system for use in time-resolved spectroscopic measurements in the visible and ultr aviolet (UV) spectral region. The laser is designed for fine tuning and hig h wavelength stability. A Nd:YAG-pumped distributed-feedback dye laser (DFD L) generates pulses that are similar to 100 ps in duration with a nearly tr ansform-limited linewidth (similar to 5 GHz) at a 20 Hz repetition rate. Th e DFDL pulses are amplified in two bow-tie amplifiers, providing pulse ener gies of up to 3.0 mJ; the amplified pulses may be frequency doubled to the UV spectral region, providing up to 1.0 mJ. The DFDL wavelength is computer stabilized to within +/- 0.8 pm (+/- 0.7 GHz, two standard deviations), al lowing the wavelength to be stationed on a narrow atomic or molecular trans ition or permitting nearly continuous spectral scans. Application of the la ser system to studies of OH energy transfer has been demonstrated; both las er-induced-fluorescence and degenerate-four-wave-mixing spectra have been r ecorded. (C) 2000 American Institute of Physics. [S0034-6748(00)05003-6].