High temperature operation of passively Q-switched, Cr:YAG/Nd:YAG micro-laser for ignition of engines

Abstract

The compact, high brightness passively Q-switched micro-lasers end-pumped by fiber-coupled LDs were developed for ignition of engines. The brightness of the micro-laser was calculated to be 0.3PW/sr-cm2 and the focused optical power intensity is estimated to be 5TW/cm2 at the pulse energy of 2.7mJ. The short pulse width of 600ps and the high beam quality of M2=1.2 can successfully reduce the ignition energy and then the laser head size comparable to a spark plug. In addition the micro-laser igniter demonstrated the acceleration of combustion and the ignition for leaner mixture gas due to the absence of electrodes. [1–5]