High-efficiency high-power InAlGaAs laser diodes at 980 nm

Within the last few years, high power laser diodes with remarkable improvements concerning output power, efficiency, and reliability have been investigated in the wavelength range between 780 nm and 1064 run. The discussion, whether laser diodes fabricated from M-free material systems can surpass the performance of devices made from the conventional InAlGaAs-material system is still ongoing. In our contribution to this discussion we present 980 nm high-power InAlGaAs-laser diodes and laser diode bars with high conversion efficiencies grown by MBE. Broad area laser diodes with 100 pm aperture show an output power as high as 9.2 W cw at room temperature. Up to this output power the conversion efficiency remains above 46 %. The highest efficiency of nearly 60 % is reached at 2.5 W of output power. Reliability tests are predicting a lifetime of at least 20.000 h at a power level of 1.5 W cw. Laser diode bars of 1 cm width comprising 25 of these oscillators have been fabricated. Similar to single emitters these devices achieve a conversion efficiency of 58 % at 62 W of cw output power. In terms of conversion efficiency and output power these results are among the best reported for both, Al-containing and Al-free laser diodes and laser diode bars.