基于偏振自稳定双环的受激Brillouin散射光电振荡器

Stimulated Brillouin Scattering Optoelectronic Oscillator Based on Self-polarization-stabilization Dual-Loop

基于偏振自稳定双环结构提出一种受激Brillouin散射(SBS)光电振荡器(OEO),利用SBS的窄带宽增益谱实现相位调制到强度调制的转换(PM-IM),并选择OEO的振荡模式,构造偏振自稳定双环结构,在每个回路中的输入光被45°Faraday旋转镜反射后,将通过45°Faraday旋转器和不同长度单模光纤返回其路径,保证输出信号和输入信号的偏振态始终相差180°,从而消除外界机械振动和温度干扰.由于环路结构为反射式往返传输,因此所需光纤长度缩短1/2.实验结果表明,该OEO通过改变泵浦光波长实现频率调谐,可产生1~16 GHz的微波信号,10 GHz处边模抑制比(SMSR)达67.14 dB,相位噪声为-116.3 dBc/Hz@10 kHz.

We proposed a stimulated Brillouin scattering(SBS)optoelectronic oscillator(O EO)based on a self-polarization-stabilization dual-loop structure.By utilizing the narrow bandwidth gain spectrum of SBS to achieve the conversion from phas e modulation to intensity modulation(PM-IM),and selecting the oscillation mode of the OEO.A polarization self-polarization-stabilization dual-loop struct ure was constructed.After the input light in each loop was reflected by a 45°Faraday rotator mirror.It would return to its path through a 45°Faraday rotator and different lengths of single-mode fiber,ensuring that the polarization state of the output signal and the input signal always differed by 180°,thereby eliminating external mechanical vibrations and tempe rature disturbances.Since the loop structure was reflective and bidirectional,the required fiber length was reduced by half.The experimental re sults show that the OEO can achieve frequency tuning by changing the pump wavelength,and can generate microwave signals of 1—16 GHz,with a side mode suppression ratio(SMSR)of 67.14 dB at 10 GHz,and a phase noise of-116.3 dB c/Hz@10 kHz.