New highly-efficient laser bars and laser arrays for 8xx-10xx nm pumping applications

摘要

High-power laser bars and laser arrays are attractive light sources for many industrial applications such as direct material processing or as pump sources for solid state and fiber lasers. There is also a great interest in quasi-CW laser bars for laser ignition and fusion applications. These applications require a continuous improvement of laser diodes for reliable operation at high output powers densities and simultaneously high electrical-to-optical efficiencies. JENOPTIK presents an overview of recent progress in the development of highly efficient CW and quasi-CW laser devices emitting in a wide wavelength range between 880 nm and 1020 nm. Laser arrays emitting in the wavelength range 915 nm to 976 nm exhibit very high efficiencies above 65%. Our technology of new generation 940 nm high fill-factor bars has been currently extended to emission wavelength of 1020 nm with excellent results: 200 W output power with 63% efficiency using passively cooled heatsinks. Additionally, performances of high brightness low fill-factor laser bars with resonator lengths of 4 mm are shown. The innovative design of the laser structure enables, moreover, the realization of 500 W - 880 nm quasi-CW laser bars with wall-plug efficiencies of 55% and a narrow fast-axis divergence angle of 40° (95% power content).