Facet coating effects on 1.3 and 1.55 μm strained multiple-quantum-well AlGaInAs/InP laser diodes

The authors investigate the influence of facet reflectivity on the threshold current, light output power, characteristic temperature and slope efficiency drop for 1.3 and 1.55 μm strained multiple-quantum-well AlGaInAs-InP laser diodes (LDs) grown by low-pressure metalorganic vapor phase epitaxy. Remarkable improvements in maximum operation temperature, threshold current, slope efficiency drop, characteristic temperature and linearity of CW light-current characteristics have been demonstrated by increasing the reflectivity of the facet coating. By applying a high-reflectivity facet coating of 70-90% to the 1.3 μm LDs and 80-90% to the 1.55 μm LDs, lower threshold currents of 8.78 and 5.4 mA at 20°C, maximum operation temperatures of 165 and 155°C, lower slope efficiency drops of -0.7 and -0.9 dB, and higher characteristic temperatures of 92 and 88 K, respectively, can be obtained by decreasing the mirror loss. In addition, the LDs with facet coating can be operated for up to 10000 h at 10 mW and 85°C without significant degradation