石英单模光纤中非线性光谱特性的实验研究  

Characteristics of Nonlinear Spectrum in Quartz Single Mode Fiber

作　　者：张鹏[1] 田春林[1] 

机构地区：[1]长春理工大学机电工程学院,吉林长春130022

出　　处：《光学学报》2016年第8期236-242,共7页Acta Optica Sinica

基　　金：国家863计划(2012AAXXX090)

摘　　要：搭建了一台用于研究石英单模光纤中非线性光谱特性的实验系统。利用磷酸钛氧钾(KTP)晶体倍频电光调Q脉冲Nd^(3+)∶YAG固体激光器,将输出脉宽为10ns,最大峰值功率达到50 MW,波长为531.81nm±0.26nm的激光作为抽运光源,抽运长度分别为250m和500m的石英单模光纤。根据马吕斯定律使用偏振片调节抽运光的输出能量。在实验系统稳定工作的条件下,调节抽运光输出能量分别为220.6kW和170kW时,获得了可见光范围内250m和500m石英单模光纤的多级非线性光谱。基于石英单模光纤中的三阶非线性理论,分析了实验中所获得非线性光谱的特性。理论分析和实验数据均表明:石英单模光纤长度越长,非线性光谱强度、耦合增益系数越大,能量阈值越低,而石英单模光纤长度越短,非线性谱线的展宽和散射附加峰的产生越容易。An experiment system is set up for studying the characteristics of nonlinear spectrum in quartz single mode fiber.The electro-optical Q-switched pulsed Nd^3＋∶YAG solid laser,frequency-doubling by potassium titanium oxide phosphate（KTP）crystal,with output pulse width of 10 ns,the maximum peak power of 50 MW,and wavelength of 531.81nm±0.26 nm,is used to pump the quartz single mode fibers with lengths of 250 mand 500m.Based on the principle of Malus law,apolarizing plate is used to adjust the output power of the pumping source.Under the stable operation condition,multi stage nonlinear spectra of 250 mand 500mquartz single mode fibers in the visible region are obtained,while the output powers of pumping sources are 220.6kW and 170 kW.Based on the principle of the third-order nonlinear effects in quartz single mode fiber,the characteristics of the nonlinear spectra obtained in the experiment are analyzed.Both the theoretical analysis and experimental results indicate that the longer the length of quartz single mode fiber,the larger the relative intensity of nonlinear spectrum and the coupling gain coefficient,and the smaller the energy threshold;while the shorter the length of quartz single mode fiber,the easier the broadening of nonlinear spectra and the generation of scattering additional peak.

关 键 词：非线性光学 单模光纤 光谱频移 受激拉曼散射 

分 类 号：O437[机械工程—光学工程]