Relative Intensity Noise Suppression for RF Photonic Links

We propose and experimentally demonstrate a novel technique to reduce laser relative intensity noise (RIN). A RIN suppression servo is usually implemented by inserting an intensity modulator in the optical path and controlling measured light intensity with a closed-loop servo system. We utilize the intensity modulator already present in a photonic link to perform the task of RIN suppression as well as encoding the optical signal with the microwave subcarrier. This technique provides suppression of 10 to 50 dB of laser RIN over a bandwidth of 10 MHz. Furthermore, we implement this technique in an optoelectronic oscillator, significantly improving its phase noise performance due to the reduced effect of RIN on the phase noise of the oscillator.