We have designed and tested a pulsed single-mode dye laser for use as the master-oscillator in a laser isotope separation system. The frequency stabilized single-mode laser with grazing-incidence diffraction grating is pumped by a 10 kHz copper vapor laser to produce up to 600 mW average power at over 30% efficiency in diffraction limited beam. A broad single-mode tuning range (without mode-hopping) of 7 nm was obtained. By using active stabilization of the cavity length, a frequency drift for long term operation within ±30 MHz and frequency width of about 100 MHz were obtained.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.