基于PPLN晶体的可调谐太赫兹波辐射特性研究  

Study on the characteristics of tunable THz-wave radiation based on the PPLN crystal

作　　者：李雪[1] 延凤平[1] 谭思宇[1] 

机构地区：[1]北京交通大学光波技术研究所,全光网络与现代通信网教育部重点实验室,北京100044

出　　处：《光电子．激光》2013年第12期2265-2269,共5页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金项目(61077069)资助项目

摘　　要：提出了一种周期极化铌酸锂(PPLN)晶体差频产生太赫兹(THz)波的新型结构。基于非线性晶体三波互作用理论模型,根据周期极化掺镁铌酸锂(PPMgLN)晶体的准相位匹配原理和掺铒光纤激光器(EDFL)双波长输出激光特性,并结合晶体折射率差公式,理论分析了工作温度及极化反转光栅周期对其输出THz波的影响,给出一定频率范围内其输出波长连续可调谐的实现方法。本文系统结构简单、成本低和调谐容易,激光器可室温运转。As research in the field of the photoelectron and electromagnetic waves continues, the development of terahertz wave has attracted more and more attention. This paper proposes a new and potential structure of the tunable and narrow-band terahertz wave （THz-wave） radiation via the nonlinear optical difference frequency generation on a periodically poled Mg-doped lithium niobate （PPMgLN） crystal. According to quasi-phase-matching （QPM） in the PPLN crystal based on the theoretical model of three wave interactions in a nonlinear medium and the output characteristics of dual-wavelength erbium-doped fiber laser,the experimental refractive index difference on the periodically poled Mg-doped lithium niobate crystal is given. Through analyzing the working temperature and the grating period on its output of the THz-wave in theory,the reliable method to generate the continuous-tunable output wave through the PPMgLN in a small frequency range is obtained. The DFG device structure is relatively simple, low cost, and the tuning is easy to implement. In addition,the laser can be operated at room temperature.

关 键 词：双波长光纤激光器 周期极化铌酸锂(PPLN) 非线性光学差频 太赫兹(THz) 

分 类 号：O441.4[理学—电磁学]