DISTRIBUTED BALANCED PHOTODETECTOR FOR RF PHOTONIC APPLICATIONS

摘要

A novel velocity-matched distributed balanced photodetector operating at 1.3 and 1.55 mum wavelengths has been proposed and experimentally demonstrated. Distributed absorption and velocity matching of the optical and microwave signals are employed to achieve high saturation photocurrent. The velocity matching between the incident optical wave and the output microwave signal allows the detector length and effective absorption volume to increase without penalizing the bandwidth. A common-mode rejection ratio greater than 27 dB has been achieved over a wide range of photocurrents. More than 24-dB suppression of the relative intensity noise of the laser source and EDF A added noise has been achieved in a broadband RF link experiment Shot-noise limited performance has been achieved with significant improvements in the signal-to-noise ratio over a wide range of frequencies and phase mismatch of input RF signals. The experimental results indicate that the distributed balanced photodetector will have a major impact on most RF photonic systems with its superior potential of reaching very high power levels.