A monolithically integrated optoelectronic receiver based on the pseudomorphic InGaAs on GaAs material system has been fabricated and tested for the first time. Quarter-micrometer modulation-doped field-effect transistors (MODFET's) with ft's of 66 GHz are used in the two-stage transimpedance amplifier design. The circuit utilizes all active components including a metal-semiconductor-metal (MSM) photodetector and a common-gate FET active feedback resistor. Transimpedances between 300 and 3000 Ω are obtained by varying the controlling gate voltage of the feedback FET. A 3-dB transimpedance bandwidth of 5.6 GHz and a transimpedance-bandwidth product of 4.8 THz-Ω are measured for the amplifier. A maximum bandwidth of 4.4 GHz is deduced from optical pulse measurements limited mainly by the transit time of photogenerated carriers across the 3 μm finger spacing of the large 100 × 100 μm2 MSM.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering