Ultra-low phase noise frequency-comb-based microwave generation and characterization

We report on the generation of ultra-low phase noise microwave signals at 12GHz by photodetecting the pulse train of an Erbium-doped fiber-based optical frequency comb phase locked to a ultra-narrow linewidth ultra-stable laser at With advanced photodetection techniques and homemade phase noise measurement apparatus, our experiment demonstrates generation of a microwave source with absolute phase noise below −170dBc/Hz at 10kHz and above, and below −100dBc/Hz at 1Hz from a 12GHz carrier, which pushes even further the best results reported so far.