多纵模光抽运重水亚毫米波激光的频谱特性  

Spectral Characteristics of Multi-Longitudinal-Mode Optically Pumped D_2O Submillimeter Wave Laser

作　　者：杨扬[1] 孟猛[1] 罗锡璋[1] 

机构地区：[1]中山大学信息科学与技术学院,广东广州510275

出　　处：《中国激光》2010年第2期404-407,共4页Chinese Journal of Lasers

基　　金：广东省自然科学基金(021757)资助项目

摘　　要：采用半经典密度矩阵理论计算了单纵模(SLM)和多纵模(MLM)脉冲光抽运重水(D_2O)分子亚毫米波(SMMW)激光三能级系统的抽运信号的吸收系数和亚毫米波激光信号的增益系数,利用迭代法数值计算了亚毫米波激光信号的频谱特性和输出光强,对频谱精细结构和激光过程的规律进行了深入的研究和比较。研究结果表明,在超辐射情况下,多纵模光抽运D_2O与单纵模光抽运相比,前者的亚毫米波激光谱线较宽;在腔式的情况下,单纵模和多纵模光抽运D_2O的亚毫米波激光谱线都进一步展宽,在频谱曲线上均呈现与多纵模结构对应的多个尖峰。Based on the semi-classical density matrix theory, the gain coefficients of infrared （IR） pumping signal and submillimeter wave （SMMW） laser signal for a three-energy-level system in single-longitudinal-mode （SLM） and in multi-longitudinal-mode （MLM） pulse optically pumped D2O SMMW laser are deduced. The spectral characteristics and output power are calculated by numerical iteration method. The laser processes and the fine structures in spectral characteristics are studied and compared in detail. MLM optically pumped D2O superradiant laser produces a wider SMMW laser line than SLM pumped laser does. In both SLM and MLM optically pumped D2O cavity lasers, SMMW laser lines broaden further and narrow peaks will appear in their spectrum. These narrow peaks correspond to the MLM structure of the SMMW laser line. The wide band spectrum and MLM structure characteristics provide a theoretical basis for frequency tunable SMMW laser.

关 键 词：激光技术 亚毫米波激光器 多纵模光抽运 重水 频谱特性 多拉曼相互作用 

分 类 号：TN248.22[电子电信—物理电子学]