Opto-electronic oscillator

An opto-electronic oscillator is based on converting the continuous light energy from a pump laser to radio frequency (RF), microwave or mm-wave signals.

Most OEOs utilize the transmission characteristics of an optical modulator together with a fiber-optic delay line to convert light energy into stable, spectrally pure RF/microwave reference signals.

This configuration supports self-sustained oscillations, at a frequency determined by the fiber delay length, the bias setting of the modulator, and the band pass characteristics of the filter.

Whispering gallery mode optical resonators are axially symmetric dielectric structures ranging in size from tens of micrometers to a few millimeters, and can trap light in a small volume.

[2] Quality factor (Q) of OEO is determined from a resonator's centre frequency f0 and group delay τ where n is the refractive index, L is the optical fibre length and c0 is the speed of light in vacuum.