Abstract

We report the use of gain switching to generate single-longitudinal-mode pulses from a laser-diode-array-excited monolithic Nd:YAG laser. The high peak power (>400 mW), long-term frequency stability (<30 MHz), and near-Fourier-transform-limited, ~75-nsec (FWHM), output of the device make it particularly suitable for the injection locking of laboratory-scale (~1/J) Nd:YAG lasers. Frequency-stable multiple-pulse operation has been demonstrated at delays as short as 4 µs and repetition rates of > 1 kHz which suggest that operation up to 250 kHz would be feasible. The device consists of three simple components: (1) a monolithic Nd:YAG resonator crystal; (2) a 100-mW cw (nominal output) laser-diode array pump source; and (3) a 0.29 pitch GRIN lens to image the pump source into the active medium. Numerical modeling of the device suggests that over 1 W of peak power could be obtained with only slight modifications in design. The application of this device as a master oscillator for injection-locking larger Nd:YAG lasers is discussed along with a novel technique for active frequency stabilization of the slave laser based on the unique properties of the monolithic master oscillator.

© 1985 Optical Society of America