High performance DP-QPSK receiver module incorporating InP-based integrated coherent detection chip

This paper presented a fully integrated InP coherent receiver chip for a dual polarization QPSK application. The chip, which has the highest responsivity reported to date, used a unique layout to benefit module assembly and minimize excess loss. The overall responsivity of a full module with VOA functionality exceeded 0.07A/W. The paper also demonstrated a miniaturized version of our chip which is suitable for future size and cost reductions.