Abstract

We have previously reported¹ a novel, diode-laser, side-pumped Nd:YVO₄ slab laser oscillator with high optical to optical conversion efficiency. This oscillator design uses a laser material such as Nd:YVO₄ which absorbs strongly at the pump wavelength so the laser gain is confined to a thin region next to the flat pump face. Good spatial overlap between the pumped volume and the laser mode is obtained by arranging the cavity optics so that the laser mode makes a single, grazing-incidence, total internal reflection from the pump face and therefore remains in the region of highest gain throughout its passage through the laser material. Because of the single reflection, the gain across the mode is symmetric resulting in a nearly diffraction limited output beam. Measurements of the threshold pump power and cavity losses indicate that the gain is very high and we have recently reported on the use of this pumping arrangement in a lossy grating-tuned, single- mode cavity.² We report here direct measurements of the small signal gain.

© 1994 Optical Society of America