15 GHz monolithic MODFET-MSM integrated photoreceiver operating at 1.55 μm wavelength

The fabrication of an extremely wide bandwidth, long wavelength integrated photoreceiver implemented with InAlAs/InGaAs/lnP MODFETS and metal-semiconductor-metal photodetectors (MSM-PDs) is presented. The transimpedance amplifier is implemented with 0.25 μm gate length FETS to achieve high operational speed. The active feedback FET employed permits the amplifier´s transimpedance to be varied from 5400 to 72 Ω. At a transimpedance of 350 Ω, a very flat optical to electrical frequency response with a -3 dB frequency of 10 GHz is achieved. For lower transimpedance gains. A moderately gain-peaked response is achieved, with measured 3 dB bandwidths of up to 15 GHz. To our knowledge, this is the fastest MODFET-based photoreceiver operating at a 1.55 μm wavelength and the only MSM-MODFET photoreceiver to have a bandwidth greater than 10 GHz