A front-side-illuminated InP/GaInAs/InP p-i-n photodiode with a —3-dB bandwidth in excess of 18GHz

High-speed front-side illuminated InP/GaInAs / InP p-i-n 1-1.6-µm photodetectors have been fabricated from materials grown by atmospheric pressure organometallic vapor phase epitaxy (OMVPE). The AR-coated devices have external quantum efficiencies of > 85 percent at 1.3 µm and the temporal response has a full-width half-maximum (FWHM) of < 18 ps. Dark current density is 6 × 10^-6A . cm^-2at an operating bias of -4 V. The interface is abrupt to two monolayers at the InP (substrate)-GaInAs heterojunction and five monolayers at the GaInAs-InP p-layer heterojunction.