Phase noise of whispering gallery photonic hyper-parametric microwave oscillators

• Published in: Optics express Vol. 16; no. 6; pp. 4130 - 4144
• Main Authors: Savchenkov, Anatoliy A, Rubiola, Enrico, Matsko, Andrey B, Ilchenko, Vladimir S, Maleki, Lute
• Format: Journal Article
• Language: English
• Published: United States Optical Society of America - OSA Publishing 17-03-2008
• Subjects: Calcium Fluoride - chemistry; Electromagnetism; Engineering Sciences; Equipment Design; Equipment Failure Analysis; Instrumentation and Detectors; Microwaves; Optics; Optics and Photonics - instrumentation; Oscillometry - instrumentation; Photonic; Photons; Physics
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/oe.16.004130

We report on the experimental study of phase noise properties of a high frequency photonic microwave oscillator based on four wave mixing in calcium fluoride whispering gallery mode resonators. Specifically, the oscillator generates approximately 8.5 GHz signals with -120 dBc/Hz at 100 kHz from the carrier. The floor of the phase noise is limited by the shot noise of the signal received at the photodetector. We argue that the performance of the oscillator can be significantly improved if one uses extremely high finesse resonators, increases the input optical power, supersaturates the oscillator, and suppresses the residual stimulated Raman scattering in the resonator. We also disclose a method of extremely sensitive measurement of the integral dispersion of millimeter scale dielectric resonators.