Auto-oscillation of a low-noise microwave signal in an optoelectronic oscillator with passive optical amplification

A detailed study of an optoelectronic oscillator with passive optical amplification has been carried out. A key feature of studied oscillator circuit is the absence of any optical or microwave amplifiers. The circuit parameters that affect the phase noise are determined. A modified Yao–Maleki model is proposed that more adequately describes the phase noise spectrum of an optoelectronic oscillator without amplifiers. The minimum phase noise obtained was -135 dBc/Hz at a 10 kHz offset from a carrier frequency of 3.5 GHz for a fiber length of 600 m. Dependence of the flicker noise coefficient on the laser power is determined, which makes it possible to characterize more accurately the phase noise of an optoelectronic oscillator with passive optical amplification.