Narrow linewidth, high PRF copper laser-pumped dye-laser oscillators

Design and operating characteristics are reported for high prf copper laser-pumped rhodamine 590 dye-laser oscillators using simple Littrow-mounted or grazing-incidence grating cavities incorporating double-prism beam expanders. Conversion efficiencies from the 2-W, X510.6-nm pump beam at the X575-nm peak of the dye tuning band are 4-5% for linewidths in the subgigahertz range down to 650 MHz at a pulse repetition frequency of 8 kHz. Background amplified spontaneous emission intensity is low, typically 1% of tunable laser intensity for the Littrow-grating cavity and only 0.1% for the grazing-incidence grating cavity.