Application Research Of Optoelectronic Oscillator

Optoelectronic oscillator(OEO)converts optical signal to microwave signal through an optoelectronic feedback loop.The OEO with advantages of frequency tunability,high Q value,and low phase noise has board application prospects in optical fiber communication,optical-controlled phased array antenna,aerspace and other fields.The relevant institutions and researchers pay extensive attention to OEO.In this thesis,we theoretically study the OEO,including its theoretical model,the simulation of spectral characteristics of single(dual)-loop structure,the simulation of phase noise model,and applications.The main research contents are as follows:(1)Research on the theoretical model of OEO.The relationship between fiber length and spectral characteristics and phase noise of OEOs is discussed by simulation and analysis of spectral characteristics and phase noise model of OEO(2)A scheme for generating optical frequency comb(OFC)based on OEO and electro-absorption modulator(EAM)is proposed.On the basis of completing the theoretical derivation,the scheme is simulated and the relationship between the relevant parameters in the scheme and the quality of the OFC is analyzed.The simulation results show that the frequency spacing of the generated OFC are 5 GHz,10 GHz,15 GHz and20 GHz,respectively,the flatness is better than 4.3 d B,and the number of spectral lines is 107 by changing the output frequency of the OEO;The number of spectral lines of the OFC increases from 37 to 107,and the flatness is better than 4.0 d B by changing the number of lasers;The flatness of the OFC is better than 4.0 d B by Varing the laser power from 0 to 12 d Bm;When the laser linewidth varies from 100 k Hz to 100 MHz,the flatness of the OFC is 3.7 d B on the laser linewidth less than 1 MHz,and the flatness of the OFC deteriorates sharply on the laser linewidth more than 1 MHz;When the extinction ratio of the modulator varies from 10 to 40 d B,the flatness of the OFC is 3.9 d B on the extinction ratio more than 30 d B,and the flatness deteriorates sharply on the extinction ratio lower than 30 d B.(3)A scheme to generate a frequency quadrupling,octupling,16-tupling,32-tupling and 64-tupling,respectively microwave signals based on the external modulation of OEO is proposed.The relationship between laser power,modulator extinction ratio and voltage offset and multi-frequency signal performance is analyzed by derivation and simulation verification of the scheme of multi-frequency.The simulation results show that the RF sideband suppression ratios(RFSSR)are 50.6 d B,47.2 d B,50.6 d B,12.7 d B and 35.1d B,respectively.(4)A scheme to generate square wave,triangular wave and sawtooth wave based on OEO and Dual-Port Dual-Drive Mach-Zehnder Modulator(DDMZM)is proposed.On the basis of completing the theoretical derivation,the influence of the extinction ratio of the modulator and the voltage offset on the waveform is analyzed by the simulation of three schemes.The simulation results show that the root mean square error(RMSE)values of the generated square wave,triangle wave and sawtooth wave and the corresponding standard theoretical waveform are 0.0899,0.0026 and 0.8099,respectively.