New strategies for fiber-based femtosecond lasers low-noise microwave generation

Low-phase-noise and stable microwave signals are of prime importance in a variety of scientific and technological fields, such as, for example, atomic frequency standards1,2, radar and remote sensing, and very long baseline interferometry. The combination of ultra-stable lasers 3 and low noise optical frequency division by use a femtosecond laser presents a possibility to realize extremely low phase noise microwave source with reliable and operational-level technology. We have previously reported phase noise levels at −120 dBc/Hz at 1Hz from a 12 GHz carrier, with white phase noise plateau approaching −140dBc/Hz 4,5,6.