作　　者： ; ; ; ;

机构地区： 清华大学信息科学技术学院电子工程系

出　　处： 《光学学报》 2013年第5期154-160,共7页

摘　　要： 报道了一种可用于产生窄带太赫兹(THz)波的超大频差双纵模Nd…YVO4激光器。该激光器基于薄片激光介质和微型腔来实现连续双纵模运转,两个纵模间的频差处于THz波段,通过调节激光器的腔长可实现频差在0.1～0.2THz范围内的调谐;单个纵模的谱线宽度仅为20MHz;激光束空间分布为单横模,光束质量M2因子为1.292;在630mW抽运光下,输出连续激光功率为116mW,斜率效率为18.53%,线偏振度为0.993。该激光器输出的双频光可被用作种子光经放大后来获得高功率THz差频抽运光,再在非线性晶体中通过共线差频就能实现窄带THz波辐射,理论分析表明THz波辐射谱线宽度约为THz差频抽运光的槡2倍,另外采用光斑半径为50μm和峰值功率在千瓦量级的THz差频抽运光,在0.8mm厚DAST晶体中可得到毫瓦量级的THz波输出。 A double-longitudinal-mode Nd, YV04 laser with ultra-large frequency difference is reported, which can be used for generating narrowband terahertz （THz） wave radiation. Continuous-wave （CW） double-longitudinal-mode operation of the laser is achieved based on the thin-disk laser medium and the micro-cavity, and the frequency difference between the two longitudinal modes is in the THz band, tuned by adjusting the length of the laser cavity and varying within the range of 0.1-0.2 THz; The spectral linewidth of each longitudinal mode is as low as 20 MHz; The spatial distribution of the laser beam is a single transverse mode with the beam quality factor M2 of 1. 292 The output power of the CW laser is 116 mW with the slope efficiency of 18.53 % and the linear polarization degree of 0. 993, when the power of the pumping light is 630 mW. Used as the seed light, the double-frequency output light of the double-longitudinal-mode laser will be amplified to obtain the high-power THz difference-frequency pumping light, which can realize the narrowband THz-wave radiation via collinear difference frequency generation in the nonlinear crystal, while the theoretical analysis indicates the spectral linewidth of the THz-wave expands to approximately times than that of the THz difference-frequency pumping light, and using the THz difference-frequency pumping light with spot radius of 50 tam and peak power in kilowatt magnitude and 0.8 mm DAST crystal, the THz-wave radiation with output power in milliwatt magnitude can be generated.

关 键 词： 激光器 双纵模 激光器 超大频差 微型腔 窄带 波辐射

领　　域： [电子电信]