Sub-50 W pico-second output from a Nd:YVO4 phase-conjugate amplifier

High-power pico-second lasers with high beam-quality have been intensely sought for various industrial and science applications, including micromachining, laser display, and nonlinear frequency conversion. This paper addresses power scaling of the system by slightly detuning a pump diode frequency from the absorption of Nd:YVO₄, and carefully utilizing a spatial filtering technique, resulting in the suppression of parasitic oscillation and an improvement of spatial overlap between the gain region and the injected laser beam, even at a higher pump level. An output power of 45.7 W is achieved from a simple picosecond phase-conjugate master-oscillator power amplifiers (PC-MOPA) just formed by a Nd:YVO₄ amplifier and a Rh:BaTiO₃ phase conjugate mirror. Further power scaling of the system is possible up to over 100 W by refinements of the pump diode and the use of a cascaded amplifier geometry in combination with a second power amplifier.