All-optical vector network analyzer with 500 GHz bandwidth and 76 MHz frequency resolution

We demonstrate an all-optical time-domain vector network analyzer with a frequency resolution of 76 MHz and a bandwidth exceeding 500 GHz in a single measurement configuration. Electrical reflection coefficients are obtained from measurements of ultra-short voltage pulses at different positions on a coplanar waveguide using femtosecond laser pulses and an asynchronous optical sampling technique. In contrast to our previous synchronous sampling experiments, the new technique leads to a significant improvement of the frequency resolution and potentially more accurate measurements being important for future calibration tasks.