Patent ID: 6784399
Filing Date: 2004-08-31
Classification: B23K,B28D,H01S,H05K

Abstract:
In a CO2 laser system having a resonator cavity that includes a gas gain medium that in response to pumping energy supplied by a pumping source produces stimulated emission energy, a method for laser micromachining, comprising:supplying pumping energy, from the pumping source at a pumping start time and throughout a pumping span, to the gas gain medium within the resonator cavity; generating from the resonator cavity a laser output of a burst of at least one laser pulse, including a first laser pulse, of stimulated emission energy from the resonator cavity during the pumping span, wherein the resonator cavity includes Q-switch that in response to an applied switching signal causes at least first and second states corresponding to respective low and high values of optical gain in the resonator cavity and influences multiple waveform characteristics of each laser pulse, wherein changing the applied switching signal from the first state to the second state at a pulse extraction start time causes extraction of each laser pulse and changing the applied signal from the second state to the first state at a pulse termination time causes termination of each laser pulse, wherein each laser pulse has a pulsewidth that includes a time interval between the pulse extraction time and the pulse termination time, wherein each laser pulse is characterized by a spike having a peak instantaneous power followed by a tail having a range of tail instantaneous powers above a nonzero value, wherein the spike has a spike duration and the tail has a tail duration that is substantially greater than the spike duration, and wherein a delay is introduced between the pumping start time and the pulse extraction time of the first laser pulse to influence the peak instantaneous power of the spike of at least the first laser pulse; and directing the burst of the laser output to remove target material at a target area.