Lens-less edge-pumped high power microchip laser
ABSTRACT We report the demonstration of compact lens-less microchip laser, which is directly pumped by single-emitter diode chips from multiple directions. The lens-less design makes the microchip laser more compact; the multi-direction designable pump schemes can realize a Gaussian shape. As a preliminary result, continuous wave output power of 32.5 W and slope efficiency of 45% was obtained by 9-direction pumped Yb:YAG ceramic microchip. Further, 27.2 W single peak Gaussian beam was obtained by a small adjustment of the output mirror. Power scalability is easy by increasing the number of diodes to 27 to achieve 100-watt-level microchip laser.