Characterization of 40 Gb/s receivers using impulse response method

Much work has gone into verifying the validity of using the impulse response for characterizing the frequency response of high-speed photodiodes and photo receivers. Here we expand on this work by showing its validity as applied to understanding 40 Gb/s digital receiver performance. We show that using a measured impulse response of a photo-receiver/50 GHz (or faster), sampling oscilloscope pair, 40 Gb/s eye diagrams can be accurately simulated. Simulation of eye diagrams is an extremely important step in understanding and predicting digital system performance. Using the impulse response method, impairments leading to eye closure can be detected without the need for expensive equipment required for experimental performance verification.