Distributed balanced photodetectors for high-performance RF photonic links

A novel velocity-matched distributed balanced photodetector with a 50-/spl Omega/ coplanar waveguide output transmission line has been experimentally demonstrated in the InP-InGaAs material system. Distributed absorption and velocity matching are employed to achieve high-saturation photocurrent. A common mode rejection ratio of 27 dB has been achieved. The RF link experiment conducted at 6.48 GHz shows that the laser intensity noise has been suppressed by more than 17 dB.