The compact Er:Yb:Glass Laser Cavity incorporates all optical components required for a short-pulse laser. These optical components are ‘locked’ into alignment forming an optical laser cavity for diode laser or flash lamp pumping. The optical laser cavity does not need optical alignment after it is fabricated. The improvement upon the original Er:Yb:Glass design replaces the Cobalt Spinel passive Q-switch component with a MEMS active Q-Switch component.