OPTIMUM STRIP WIDTH FOR CONTINUOUS OPERATION OF GAAS JUNCTION LASERS

The continuous (cw) operation of 41 GaAs junction lasers bonded on identical copper heat sinks is investigated for different widths of the stripe metallic contact (S = 5.0, 12.7, 25.4, and 50.8 μ). The highest cw operating temperatures are consistently found for S = 12.7 μ. This behavior is in agreement with computer calculations which predict an optimum" stripe width between 10 and 15 μ and a sharp reduction in cw operating temperature for S < 10 μ. The calculations are based on experimentally measured threshold current densities (Jth) at 77°and 297°K which show that Jth increases by factors of 2 or 3 when S is reduced from 12.7 to 5.0 μ. Intensity scans of mode patterns at the laser mirrors suggest that these increases in Jth are due to the effect of the unpumped regions along the junction plane on the laser mode. © 1969 The American Institute of Physics."