Low cost lattice-engineered 1.3-155 um wavelength waveguide/detector/MMIC OEICs for broadband communication systems

Using molecular beam epitaxy (MBE) and lattice engineering techniques, the feasibility of combining photonic devices applicable to the 1.3 to 1.55 /spl mu/m wavelength range and monolithic microwave (or mm-wave) integrated circuits (MMICs) on GaAs is demonstrated. A key factor in the MBE growth is incorporation of an InGaAs active layer having an indium arsenide mole fraction of 0.35 or greater and its lattic compatibility with the underlying semi-insulating GaAs substrate. The InGaAs layer used for the photonic devices can also serve as the active channel for the pseudomorphic high-electron-mobility transistors (PHEMTs) for application in MMICs. The material structure includes a 3-layer AlGaAs/GaAs/AlGaAs optical waveguide and a thin InGaAs absorbing layer situated directly above the optical waveguide. Metal-semiconductor-metal (MSM) photodetectors are formed on the top surface of the InGaAs layer for collection of the photo-induced carriers. Initial measurements are presented.