Generation of Q-switched Er:YAG laser pulses using evanescent wave absorption in ethanol

Abstract

We report on a technique of passively Q switching an Er:YAG laser operating at 2.94 μm. The Q switch consists of a high refractive index prism having one total internal reflection surface in contact with an absorbing liquid. The initial losses were achieved via attenuated total reflection. Using the above Q switch, pulses with up to 85 mJ having 130-140 ns pulse width were generated. The output was linearly polarized and the spacial beam profile was near TEM00. The laser was operated at 2 Hz repetition rate. © 1998 American Institute of Physics.