Microwave Photonics Low Phase Noise RF Comb Generator for D- and J-Band

We present a microwave photonic RF comb generator based on a quartz-stabilized, ultra-low phase noise fs pulse laser in combination with high-speed RF waveguide coupled photodetectors. With 325 GHz, the cutoff frequency of the subsystem exceeds the state of the art and enables broadband microwave comb generation with 1 GHz spacing in the D- and J band, when changing the photodetector from a WR6.5 to a WR3.4 device. We generate microwave tones at 270 GHz with a phase noise of -81 dBc/Hz at 1 kHz frequency offset and below -130 dBc/Hz at 1 MHz offset while achieving a spectral width below 1.7 Hz in the electrical domain.