The design and performance of a 10 GHz bandwidth hybrid PIN receiver for coherent optical systems

A broadband optical receiver suitable for coherent system applications is described. The simple hybrid construction utilises commercial devices throughout and comprises a single InGaAs PIN followed by a low noise HEMT amplifier in a high impedance configuration. The measured 3 dB bandwidth is 10 GHz, with substantially flat magnitude and group delay responses extending up to 8 GHz. Receiver noise does not exceed 13 pA/ square root Hz, and hence realisable local oscillator power levels produce little sensitivity penalty.<
>