Resolution improvement of the large bandwidth and high-speed electrical spectrum analyzer based on dual optical frequency combs

An all-optical electrical spectrum analyzer is demonstrated based on dual optical frequency combs and microwave photonics, and it improves the resolution to be 250 MHz over 10-GHz bandwidth, with the 1-kHz frame rate. The spectrum is directly obtained in the time domain, using as low as 10-MHz acquisition bandwidth, without any post-processing.