A Coherent Optical Transponder is a device used in optical communication systems to transmit and receive data over fiber optic networks using coherent detection techniques. Coherent detection involves using a local oscillator laser to mix the incoming optical signal with a reference signal, allowing for the extraction of both the amplitude and phase information of the optical signal. This method enables high-capacity, long-distance transmission with improved signal quality and noise resilience.


4D Optical Link Tomography: First Field Demonstration of Autonomous Transponder Capable of Distance, Time, Frequency, and Polarization-Resolved Monitoring

We report the first field demonstration of 4D link tomography using a commercial transponder, which offers distance, time, frequency, and polarization-resolved monitoring. This scheme enables autonomous transponders that identify locations of multiple QoT degradation causes.