Monolithically integrated mid-IR interband cascade laser and photodetector operating at room temperature

摘要

We report on the demonstration of a monolithically integrated mid-IR interband cascade (IC) laser and photodetector operating at room temperature. The base structure for the integrated laser and detector is a six-stage type-Ⅰ IC laser with GaInAsSb quantum well active regions. The laser/detector pair was denned using focused ion beam milling. The laser section lased in cw mode with an emission wavelength of ～3.1 μm at 20 ℃ and top-illuminated photodetectors fabricated from the same wafer had Johnson-noise-limited detectivity of 1.05 × 10~9 cm Hz~(1/2)/W at this wavelength and temperature. Under the same condition, the detectivity for the edge illumination configuration for the monolithically integrated laser/photodetector pairs is projected to be as high as 1.85 × 10~(10)cm Hz~(1/2)/W, as supported by experimentally observed high photocurrent and open-circuit voltage. These high performance characteristics for monolithically integrated IC devices show great prospects for on-chip integration of mid-IR photonic devices for miniaturized sensors and on-chip optical communication systems.