Single-longitudinal mode Nd:YVO4 microchip laser with orthogonal-polarization bidirectional traveling-waves mode.

ABSTRACT

We present a single longitudinal mode, diode pumped NdYVO(4) microchip laser where a pair of quarter-wave plates (QWPs) sandwich NdYVO(4) and the principle axes of QWPs are oriented at 45 degrees to the c-axis of NdYVO(4). Three pieces of crystals were optically bonded together as a microchip without adhesive. Owing to large birefringence of NdYVO(4), two standing waves with orthogonal polarizations compensate their hole-burning effects with each other, which diminish total spatial hole-burning effects in NdYVO(4). The maximum pump power of greater than 25 times the threshold for single longitudinal mode operation has been theoretically shown and experimentally demonstrated. The power of output, slope efficiencies and temperature range of single longitudinal mode operation are greater than 730 mw (at 1.25 W pump), 60% and 30 degrees C, respectively.