Measurement of eye diagrams and constellation diagrams of optical sources using linear optics and waveguide technology

We demonstrate the characterization of optical sources with high sensitivity, high temporal resolution, and phase sensitivity using linear optical sampling. Eye diagrams and constellation diagrams are reconstructed using the interference of the source under test with a train of sampling pulses. This concept is implemented using a waveguide optical hybrid, which splits and recombines the sources and adjusts the phase between the recombined signals to provide optimal detection. This diagnostic is used to characterize on-off keyed (OOK) waveforms at rates up to 640 Gb/s and various phase-shift keyed (PSK) signals at 10 and 40 Gb/s.