Real-time all-optical performance monitoring using optical bit-shape correlation

A new optical performance monitoring technique of an optical link in real time is experimentally demonstrated. Rather than comparing bit streams or analyzing eye diagrams, we use a novel optical correlator to compare the shapes of the individual received bits to a standard. The all-optical correlator outputs a pulse whose strength directly measures the degradation of the bit during transmission. Results are produced within three bit periods in real time instead of requiring statistical analysis of long data streams. The correlator is based on a simplified White cell-based true-time delay device.