Fig. 4: Optical difference frequency division measurements.
From: Magic cancellation point for vibration resilient ultrastable microwave signal synthesis
a Measured frequency response of the ODFD system against applied vibration in the Z direction. The response is compared for an ODFD system having two SBS lasers operating with the same and cross polarization states.. A second order response is fit to each of the measured vibration response functions. b Measured phase noise of the 10 GHz ODFD system compared to the phase noise of the base SBS lasers, the difference frequency between the SBS lasers, and the 10 GHz DRO oscillator. c Comparison of phase noise and acceleration sensitivity across several free-running microwave oscillator technologies at 10 GHz. STW surface transverse wave, OEO optoelectronic oscillator; ACCRO air-dielectric ceramic-cavity resonator oscillator, OCXO oven controlled crystal oscillator, SLCO sapphire loaded cavity oscillator. Our phase-locked ODFD performance is also plotted.
