Abstract: An apparatus and method for an efficient, passively Q-switched microlaser producing high peak power pulses of light of extremely short duration are disclosed. This microlaser utilizes Yb3+:YAG as the gain medium instead of conventionally used Nd3+:YAG or Nd3+:YVO4 gain media The utilization of the Yb3+:YAG allows superior performance of high peak-power microlaser in many aspects with respect to conventionally used Nd3+:YAG as the gain media. The efficiency of the pump of said microlaser (the so called optical-to-optical efficiency) can be higher by factor of two to four, with respect to Nd:YAG based, provided all other output parameters such as pulsewidth, output peak power and spatial quality of the beam being equal. The improved efficiency allows reducing the cost and size of the whole microlaser system substantially.

Abstract: A pulsed laser is provided wherein the B-integral accumulated in the laser pulse is reduced using a semiconductor wafer. A laser pulse is generated by a laser pulse source. The laser pulse passes through a semiconductor wafer that has a negative nonlinear index of refraction. Thus, the laser pulse accumulates a negative B-integral. The laser pulse is then fed into a laser amplification medium, which has a positive nonlinear index of refraction. The laser pulse may make a plurality of passes through the laser amplification medium and accumulate a positive B-integral during a positive non-linear phase change. The semiconductor and laser pulse wavelength are chosen such that the negative B-integral accumulated in the semiconductor wafer substantially cancels the positive B-integral accumulated in the laser amplification medium. There may be additional accumulation of positive B-integral if the laser pulse passes through additional optical mediums such as a lens or glass plates.