InP-based MMIC components for an optical phase-locked loop

Gilbert-cell and photoreceiver circuits were designed for an integrated optical phase-locked loop (OPLL) to generate stable channel offsets in dense wavelength-division multiplexing (DWDM). These circuits were fabricated using a p-i-n/heterojunction bipolar transistor layer structure. Various configurations of an OPLL employing Gilbert-cell phase detectors and photoreceiver circuits were tested, and wavelength separations from 1.0 to beyond 27.11 GHz were obtained.