In this work,the generation of high signal-to-noise ratio(SNR)single-frequency microwave signal without noise sidebands is demonstrated based on the interaction of integrated all-fiber lasers.The microwave signals are...In this work,the generation of high signal-to-noise ratio(SNR)single-frequency microwave signal without noise sidebands is demonstrated based on the interaction of integrated all-fiber lasers.The microwave signals are generated by the interference between a narrow linewidth Brillouin pump light from a single-frequency laser and the Stokes light generated by it.Firstly,the linewidths of the Stokes lights are compressed to~43 Hz based on the stimulated Brillouin scattering(SBS)effect,which ensures that the frequency noise is as low as possible.And then,the relative intensity noise(RIN)of the first order Stokes light is reduced by 21 dB/Hz based on the noise dynamics principle in cascaded SBS effect.By simultaneously reducing the frequency noise and the intensity noise of the coherent signals,the noise sidebands of microwave signals are completely suppressed.As result,the SNR of the microwave signal is improved from 48 dB to 84 dB at the first-order Brillouin frequency shift of 9.415 GHz.Meanwhile,a microwave signal with a SNR of 70 dB is generated at the second-order Brillouin frequency shift of 18.827 GHz.This kind of microwave signals with narrow linewidth and high SNR can provide higher detection resolution and higher transmission efficiency for applications on radar,satellite communication and so on.展开更多
针对2.0~25.0μm波段传输的限制损耗问题,文章采用数值模拟方法研究影响碲基硫系光子晶体光纤(photonic crystal fiber,PCF)限制损耗的主要因素。光纤纤芯和包层材料采用Ge 20 As 20 Se 15 Te 45玻璃,通过改变纤芯直径、空气孔直径和空...针对2.0~25.0μm波段传输的限制损耗问题,文章采用数值模拟方法研究影响碲基硫系光子晶体光纤(photonic crystal fiber,PCF)限制损耗的主要因素。光纤纤芯和包层材料采用Ge 20 As 20 Se 15 Te 45玻璃,通过改变纤芯直径、空气孔直径和空气孔层数等参数进行2.0~25.0μm波段限制损耗的计算,结果表明,影响限制损耗的最大因素是纤芯直径,限制损耗随着纤芯直径和空气孔直径的增大而显著降低,随着空气孔层数的增加而降低;优化设计出一种低限制损耗的PCF,结果表明,当纤芯直径和节距为8.0μm、空气孔直径为7.2μm、包层空气孔层数为4时,该PCF在2.0~25.0μm波长范围的限制损耗低于1.4×10^(-6) dB/m,满足低损耗传输要求。文章研究结果对2.0~25.0μm波段光信号的传输具有一定的意义。展开更多
文摘In this work,the generation of high signal-to-noise ratio(SNR)single-frequency microwave signal without noise sidebands is demonstrated based on the interaction of integrated all-fiber lasers.The microwave signals are generated by the interference between a narrow linewidth Brillouin pump light from a single-frequency laser and the Stokes light generated by it.Firstly,the linewidths of the Stokes lights are compressed to~43 Hz based on the stimulated Brillouin scattering(SBS)effect,which ensures that the frequency noise is as low as possible.And then,the relative intensity noise(RIN)of the first order Stokes light is reduced by 21 dB/Hz based on the noise dynamics principle in cascaded SBS effect.By simultaneously reducing the frequency noise and the intensity noise of the coherent signals,the noise sidebands of microwave signals are completely suppressed.As result,the SNR of the microwave signal is improved from 48 dB to 84 dB at the first-order Brillouin frequency shift of 9.415 GHz.Meanwhile,a microwave signal with a SNR of 70 dB is generated at the second-order Brillouin frequency shift of 18.827 GHz.This kind of microwave signals with narrow linewidth and high SNR can provide higher detection resolution and higher transmission efficiency for applications on radar,satellite communication and so on.
文摘针对2.0~25.0μm波段传输的限制损耗问题,文章采用数值模拟方法研究影响碲基硫系光子晶体光纤(photonic crystal fiber,PCF)限制损耗的主要因素。光纤纤芯和包层材料采用Ge 20 As 20 Se 15 Te 45玻璃,通过改变纤芯直径、空气孔直径和空气孔层数等参数进行2.0~25.0μm波段限制损耗的计算,结果表明,影响限制损耗的最大因素是纤芯直径,限制损耗随着纤芯直径和空气孔直径的增大而显著降低,随着空气孔层数的增加而降低;优化设计出一种低限制损耗的PCF,结果表明,当纤芯直径和节距为8.0μm、空气孔直径为7.2μm、包层空气孔层数为4时,该PCF在2.0~25.0μm波长范围的限制损耗低于1.4×10^(-6) dB/m,满足低损耗传输要求。文章研究结果对2.0~25.0μm波段光信号的传输具有一定的意义。
