Millimeter-wave long-wavelength integrated optical receivers grown on GaAs

Compact monolithically integrated narrow-band photoreceivers with a high responsivity at millimeter-wave frequencies were realized. In these receivers, a 1.3-1.55-μm wavelength In/sub 0.53/Ga/sub 0.47/As p-i-n photodiode, grown lattice relaxed on GaAs, is conjugately matched to a two-stage narrow-band amplifier based on 0.15-μm GaAs based dual-gate PHEMTs. A first receiver, designed for operation around 42 GHz, obtains an optical responsivity of 7 A/W. This is a 38-dB increase in comparison with the measured responsivity of a terminated p-i-n photodiode. For a second receiver, operating at 58 GHz, a responsivity of 2.5 A/W is obtained. These receivers are, to our knowledge, the first high-gain millimeter-wave long-wavelength photoreceivers monolithically integrated on GaAs. Their high responsivity makes them attractive for use in various microwave and millimeter-wave-over-fiber applications.