Field-deployable Photonic Microwave Synthesizer

We present the progress towards a transportable photonic microwave synthesizer, porting ultra-high optical stability to a 12 GHz signal. The system is composed of two main sub-units: a 194 THz transportable ultra-stable laser with sub-Hz linewidth and an ultra-low noise optical frequency comb used for dividing such optical frequency to the microwave domain. Characterizing the signal by means of a self-made cross-correlator, a phase noise power spectral density of −170 dBc/Hz at 10 kHz Fourier frequency is measured. This result surpasses the performance demonstrated with transportable Cryogenic Sapphire Oscillator.