Modulation response (S21) of the coupled opto-electronic oscillator

We report on the derivation of an analytical model for the modulation response (S
₂₁
) of an open RF loop for the coupled opto-electronic oscillator (COEO). The small signal linearized model takes into account the effect of positive feedback in the optical loop of the COEO, and predicts the associated Q enhancement. Other effects, such as mode matching between the loop modes and the microresonator modes, and the effect of linear cavity configuration, are studied as well. The model is backed up by experimental results. Phase noise of a short fiber COEO is also presented