掺镱混沌光纤激光倍频产生绿光混沌激光的随机特性研究  

Randomness of Green Chaotic Laser Generated by Frequency Doubling of Ytterbium⁃Doped Fiber Chaotic Laser

作　　者：邵志超 杨玲珍[1,2] 李义松 冯含露 李佳 王娟芬 Shao Zhichao;Yang Lingzhen;Li Yisong;Feng Hanlu;Li Jia;Wang Juanfen(College of Electronic Information and Optical Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;Key Laboratory of Advanced Transducers and Intelligent Control System,Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China)

机构地区：[1]太原理工大学电子信息与光学工程学院,山西太原030024 [2]太原理工大学新型传感器与智能控制教育部重点实验室,山西太原030024

出　　处：《中国激光》2024年第14期54-60,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(61975141,61575137,61675144)。

摘　　要：采用非线性晶体倍频掺镱光纤混沌激光实现了波长为535 nm的绿色混沌激光的输出。基于光纤的非线性效应获得了1070 nm混沌激光,对产生的混沌激光进行功率放大,通过控制泵浦电流的大小和倍频实现了不同功率535 nm绿色混沌激光的输出。利用排列熵、偏度、峰度对混沌激光的随机性进行分析,并对比分析倍频前后混沌激光随机性的变化。结果表明:在泵浦电流从4 A增大到10 A的过程中,1070 nm混沌激光的排列熵趋于稳定;当泵浦电流大于5.25 A时,随着泵浦电流的增大,535 nm绿色混沌激光的排列熵先下降后趋于稳定,偏度和峰度的值也趋于稳定,实验获得了时间序列随机性较好且符合正态分布的535 nm绿色混沌激光。Objective Chaotic lasers have a strong anti-interference ability, wide bandwidth, and good randomness. They are widely used in chaotic secure communication, random number generation, and optical fiber sensing. A fiber laser can generate a chaotic laser by the nonlinear Kerr effect of the fiber. Visible-wavelength chaotic lasers can be used in detecting hemoglobin concentrations, blood flow velocity, and fat foreign bodies, and in underwater ranging and other fields. In this study, a green chaotic laser with a wavelength of 535 nm is developed using a frequency-doubled ytterbium-doped fiber chaotic laser and nonlinear crystal. The output of the green chaotic laser at different powers is achieved by adjusting the pump current. The randomness of the green chaotic laser is analyzed using permutation entropy, skewness, and kurtosis.Methods Figure 1 shows the experimental setup of the 535 nm green chaotic laser. The setup is composed of an ytterbium-doped fiber chaotic laser, fiber amplifier, and frequency-doubling crystal. The 1070 nm chaotic laser is generated by adjusting the polarization controller(PC) and pump current. The ytterbium-doped fiber chaotic laser is composed of a 980 nm pump source 1(LD 1),wavelength division multiplexer 1(WDM 1), ytterbium-doped fiber 1(YDF 1), single-mode fiber(SMF), polarization-independent isolator 1(ISO 1), and coupler(OC). The YDF 1 with a length of 4 m is used as the gain medium to produce a chaotic laser with a wavelength of 1070 nm. The SMF with a length of 500 m is used to enhance the nonlinear effect in the cavity. The chaotic fiber amplifier is composed of isolators 2 and 3(ISO 2 and ISO 3), 980 nm pump sources 2 and 3(LD 2 and LD 3), wavelength division multiplexers 2 and 3(WDM 2 and WDM 3), a ytterbium-doped fiber 2(YDF 2), a double-cladding ytterbium-doped fiber(DCYDF)with a cladding pump absorption of 4.95 dB/m @975 nm, and a cladding power stripper(CPS). The YDF 2 with a length of 4 m is used for pre-amplification. The DCYDF with a length of 5 m is used to amplify the

关 键 词：激光器 掺镱光纤激光器 绿色混沌激光 倍频 随机性 

分 类 号：O439[机械工程—光学工程]