High efficiency 600 W, 100 μm wavelength stabilized fiber coupled laser diode module for fiber laser pumping

摘要

High brightness, high efficiency laser sources become more and more promising in diode laser applications for fiber laser pumping and materials processing. Dense wavelength beam combining (DWBC) technology has great advantages over other beam combining technologies as the brightness is significantly improved. However, the brightness and efficiency of DWBC technology based on laser diode bars are naturally limited by the laser source due to smile effect and low polarization ratio. By employing single emitter based DWBC technology and optimizing the optical design, a laser diode module capable of delivering above 600 W at 976 nm in a 0.22 NA 100/120 fiber is developed and 48% power conversion efficiency is achieved. The maximal power conversion efficiency, 51%, is reached at 400 W output. The intrinsic wavelength stabilization of DWBC technology allows the use of the module for efficiently pumping.