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1.95-µm-wavelength InGaAs/InGaAsP Laser with Compressively Strained Quantum Well Active Layer

In this study, we demonstrate the low pressure metalorganic chemical vapor deposition growth of highly compressively strained quantum well structures with large well thickness for extending the emission wavelength of InGaAs/InGaAsP lasers. By comparing the photoluminescence characteristics of quantum wells grown at different temperatures, it is clarified that a relatively high quality quantum well layer emitting at 2.0 µ m can be obtained at a growth temperature of 650° C. At 20° C, an 880-µ m-long double quantum-well laser operating at 1.946 µ m exhibits a threshold current as low as 14.6 mA, maximum output power higher than 10 mW and external differential quantum efficiency of 18.5%. The characteristic temperature is as high as 50 K.