Patent ID: 6414980
Filing Date: 2002-07-02
Classification: B33Y,G02F,H01S

Abstract:
A method for operating laser for performing a laser processing operation, the laser having a laser-resonator including a gain-medium and one or more-optically nonlinear crystals located outside the resonator for converting laser radiation delivered by the resonator into frequency converted radiation, the power of the frequency-converted radiation being dependent on delivery parameters of the laser radiation from the laser-resonator, the gain-medium exhibiting a thermal-lensing effect on being optically pumped, said thermal-lensing being dependent on the difference between the power of the optical pumping and the average power of laser radiation delivered by the laser resonator, and with the resonator being configured to compensate for a predetermined range of the thermal-lensing, the method comprising the steps of:(a) during the following steps, continuously optically pumping the gain medium at essentially constant power; (b) providing a Q-switch in the resonator for operating the laser to deliver laser radiation in response to said continuous optical pumping; (c) operating the laser via the Q-switch to deliver laser radiation to the one or more optically-nonlinear crystals in a first mode with delivery parameters thereof being such that frequency-converted radiation generated therefrom has insufficient peak power to perform the laser processing operation; (d) following step (c), operating the laser via the Q-switch to deliver laser radiation to the one or more optically-nonlinear crystals in a second mode in the form of a train of pulses with delivery parameters thereof being such that pulses in a train of pulses of frequency-converted radiation have sufficient peak power to perform the laser processing operation; and (e) during steps (c) and (d) operating the laser via the Q-switch such that the difference between optical pumping power and average power of the laser radiation delivered by the laser resonator provide that the thermal-lensing effect is within the compensated range.