Ring oscillators with monolithically integrated-optical readout based on GaAs-AlGaAs FET-SEED technology

Ring oscillators having integrated-optical readout are realized in GaAs-AlGaAs field-effect transistor self-electro-optic-effect-device (FET-SEED) technology-a monolithic integration technology for FET's and normal-incidence multiple-quantum-well modulators and detectors. Good agreement between simulated and measured DC-inverter-transfer characteristics is shown. At one bias point, ring oscillator frequencies correspond to unity fan-in and fan-out delay values of 129.5 ps/stage. The power-delay product at this bias point was 306 fj. Measurements were made on circuits whose transistors had a transconductance of about 80 mS/mm. Simulations of inverter delay are discussed, including load capacitances, and are found to be in good agreement with experiment.<
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