Generation of an ultra low phase noise and highly stable optoelectronic oscillator signal using an Injection-locked Technique

A new approach for the design of an optoelectronic oscillator (OEO) based on an injection-locked (IL) technique is introduced. In the IL OEO, a highly stable microwave reference resource can be used as external frequency reference in IL for side mode suppression and phase noise reduction at low offset frequencies relative to a free running oscillator. With the proposed method, we obtained a highly stable 9.5 GHz microwave signal with the phase noise level of -125 dB/Hz at 1 kHz offset frequency, -143 dBc/Hz at 10 kHz offset frequency, the side mode suppression ratio (SMSR) is larger than 40 dB.