Optoelectronic Frequency Synthesizer With World-Record Phase Noise

In this demo we show an ultra-low phase noise optoelectronic PLL (OEPLL) based on optical clock source. The output signal of this type of PLL is in the electrical domain and its reference oscillator, typically a mode-locked laser, operates in the optical domain. The OEPLL has a frequency range of 2-20 GHz. The OEPLL has an in-band phase noise of below -150 dBc/Hz at 100-kHz offset frequency for a carrier frequency of 10 GHz. This phase noise level is 10–20 dB better than state-of-the-art commercial frequency synthesizers.