THE OPTIMUM FACET REFLECTIVITIES FOR HIGH-POWER AND HIGHLY RELIABLE OPERATION OF 980-NM INGAAS ALGAAS FP LASER-DIODES/

980-nm InGaAs/AlGaAs Fabry-Perot ridge waveguide laser diodes were fab ricated for pumping Er-doped fiber amplifiers (EDFAs). The dependence of the output power on the facet coatings was investigated theoretical ly and experimentally. The expected output power was not achieved by d ecreasing the reflectivity at the front facet. It was found that a lar ge mirror loss yields an increase in internal loss due to longitudinal and lateral spatial hole-burnings, which significantly affect the dif ferential quantum efficiency of the devices. Taking the hole burning e ffects into account, the front facet reflectivity was optimized so tha t the operating current was minimum for a given output power.