1.3 μm monolithically integrated waveguide-interdigitated metal-semiconductor-metal photodetector on a GaAs substrate

Abstract
An InGaAs/GaAs strained-layer single quantum well waveguide-photodetector combination operating at a wavelength of 1.3 μm was fabricated on a GaAs substrate. An interdigitated metal-semiconductor-metal detector was deposited on top of the waveguide using Ti/Pt/Au for Schottky contacts. As expected, the responsivity of the detector increased with increasing single quantum well absorption in the waveguide and was sensitive to the polarization of the incident light. For TM polarization the responsivity of the detector was an order of magnitude lower at 1284 nm, compared to TE polarization, and exhibited weak dependence on wavelength, consistent with the transmission data. These results demonstrate for the first time a monolithically integrated 1.3 μm waveguide photodetector fabricated on a GaAs substrate.