Research On Self-Oscillation Multicarrier Light Source Based On Recirculating Frequency Shift Loop

Multicarrier light source can simultaneously output multiple optical carriers with equal frequency interval.It has great application potential in the fields of optical communication,optically controlled phased array radar,microwave photonics and laser measurement.In this paper,a self-oscillation multicarrier light source based on recirculating frequency shift loop(RFSL)is studied theoretically and experimentally.Combining the advantages that RFSL can generate wide-range multicarrier optical signal and the advantages that optoelectronic oscillation system can obtain low phase noise radio frequency(RF)electrical signal,this paper studies the self-oscillation multicarrier light source without independent RF source driving theoretically and experimentally,and studies the self-oscillation conditions and typical parameters of multicarrier light source.Focusing on the self-oscillation multicarrier light source,the main contents of this paper are as follows:1.Theoretical study on self-oscillation multicarrier light source.The principle of RFSL to achieve multicarrier output and the working mechanism of the optoelectronic oscillation system to obtain low phase noise RF signal are studied theoretically.On this basis,the theoretical model of self-oscillation multicarrier light source based on RFSL is studied.The conditions for establishing self-oscillation and the the principle of realizing multicarrier optical signal output are analyzed.The main parameters such as the number of subcarriers,frequency interval,power spectrum flatness and phase noise of self-oscillation multicarrier light source are studied as well as its advantages.2.Experimental study on self-oscillation multicarrier light source.In the experiment,the multicarrier optical signal output of RFSL driven by an independent RF source and the RF signal output by optoelectronic oscillation system are studied respectively.On this basis,the self-oscillation multicarrier light source based on RFSL is studied experimentally.27-60 subcarriers with a frequency interval of ～10.0 GHz and power spectrum flatness of ～1.46 d B are obtained.The phase noise at 10 k Hz frequency offset is ～-91.68 d Bc/Hz,which is 13.32 d B lower than the multicarrier phase noise generated by independent RF source driving.By controlling the center frequency of the electrical filter,the tunable self-oscillation multicarrier light source is simulated and experimentally studied,and the multicarrier optical signals with frequency intervals of 7.5 GHz,10.0 GHz and 12.5 GHz are obtained.