High-speed optical response of pseudomorphic InGaAs high electron mobility transistors

The optical responses of very high-frequency pseudomorphic InGaAs HEMTs with f/sub T/ of 140 GHz were obtained. These measurements were done using the picosecond time domain optoelectronic technique at room and low temperatures. The optical photovoltaic responses of these HEMTs show FWHM values of 8.4 and 7.5 ps at room temperature and 20 K, respectively. Photoconductive responsivity as high as 4 A/W with an external quantum efficiency of >600% is reported.<
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