Optical performance of a burst-mode multikilowatt CO(2) laser

A unique advancement in the flexibility of high-power lasers is presented. Operation of a 20-kW, continuous-wave, CO(2) laser with a burst excitation technique produces a broad range of optical output characteristics. A detailed discussion of the discharge excitation of this system demonstrates some unique features of the process. Control of burst frequency and duty cycle provides a convenient means to alter the time-varying nature of the output beam. Laser output can be varied from distinct, independent pulses through to a continuous wave. Optical pulse shape varies from triangular to square in profile. The primary focus of this study lies in the regime with distinct, separate pulses. Empirical relationships that summarize the dependence of optical duty cycle and peak laser power on discharge control parameters are developed. Use of these relations imparts control of the optical parameters of importance in deep penetration welding.