基于PPLN晶体的可调谐太赫兹波辐射特性研究

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。

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

As research in the field of the photoelectron and electromagnetic wave s continues,the development of terahertz wave has attracted more and more attent ion.This paper proposes a new and potential structure of the tunable and narrow-band terahertz wave (THz-wave) radiation via the nonlinear optical diff erence 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-wavel ength erbium-doped fiber laser,the experimental refractive index difference on the periodically po led Mg-doped lithium niobate crystal is given.Through analyzing the working temperature and t he grat ing period on its output of the THz-wave in theory,the reliable method to generate the conti nuous-tunable output wave through the PPMgLN in a small frequency range is obtained.The DFG device s tructure is relatively simple,low cost,and the tuning is easy to implement.In addition,the l aser can be operated at room temperature.