Velocity-matched distributed photodetectors and balanced photodetectors with p-i-n photodiodes

We report on the first demonstration of velocity-matched distributed photod etectors and balanced photodetectors with p-i-n photodetectors. Record-high linear dc photocurrent of 45 mA has been achieved without suffering from t hermal damage, thanks to the superior power handling capability of p-i-n ph otodiodes. A novel fiber alignment technique has been developed to achieve high linear photocurrent. More than 37 dB of common-mode-rejection ratio an d 45-dB suppression of laser relative intensity noise over a broad frequenc y range have been achieved using the distributed balanced photodetectors in an RF fiber-optic link. The frequency response is flat from 1 to 35 GHz.