The research on a low phase noise self-oscillating multicarrier light source

A novel scheme of a low phase noise self-oscillating multicarrier light source is proposed and experimentally demonstrated in this paper. The recirculating frequency shift loop is incorporated into an optoelectronic loop to generate low phase noise optical multicarrier signal with large number of subcarriers and high flatness. Low phase noise radio-frequency (RF) signal is generated by the frequency selection from an optoelectronic oscillating loop without the need of an external RF source, which significantly optimizes the phase noise of the multicarrier. In the experiment, multicarrier containing 60 subcarriers ranging from 1550.62 nm to 1555.35 nm with 10.0GHz frequency interval is successfully achieved, and the measured phase noise is −91.68 dBc/Hz (the real phase noise should be lower than −115.12 dBc/Hz) at 10 kHz offset frequency.