OPTICAL-PERFORMANCE OF A BURST-MODE MULTIKILOWATT CO2-LASER

A unique advancement in the flexibility of high-power lasers is presen ted. Operation of a 20-kW, continuous-wave, CO2 laser with a burst exc itation technique produces a broad range of optical output characteris tics. A detailed discussion of the discharge excitation of this system demonstrates some unique features of the process. Control of burst fr equency and duty cycle provides a convenient means to alter the time-v arying nature of the output beam. Laser output can be varied from dist inct, independent pulses through to a continuous wave. Optical pulse s hape varies from triangular to square in profile. The primary focus of this study lies in the regime with distinct, separate pulses. Empiric al relationships that summarize the dependence of optical duty cycle a nd peak laser power on discharge control parameters are developed. Use of these relations imparts control of the optical parameters of impor tance in deep penetration welding. (C) 1996 Optical Society of America