High-power linear balanced InP photodetectors for coherent analog optical links

We demonstrated an integrated InP high-power dual pair balanced uni-traveling carrier photo-detector. Each pair delivers over 1 W of RF output power into a 50 Ω load at 2 GHz which is 6 dB higher than a discrete diode of the same junction diameter. The responsivity is 0.65 A/W and the common mode rejection ratio of the balanced diode pair was measured to be greater than 40 dB. The OIP3 was measured to be 48 dBm for one balanced pair of diodes. This balanced dual pair photo-detector is very well suited for enhancing the performance of coherent analog microwave photonic links.