光泵NH,3分子亚毫米波激光的模式竞争-无线电物理专业论文.docxVIP

论文题目：光泵NH3分子亚毫米波激光的模式竞争专 论文题目：光泵NH3分子亚毫米波激光的模式竞争 专 业：无线电物理 硕士生：陈伟斌 指导教师：罗锡璋教授 摘要 本论文采用半经典密度矩阵理论对亚毫米波四能级系统进行计算，研究光泵 N魄分子亚毫米波激光的模式竞争。推导了四能级系统的激光介质的增益表达式， 采用迭代法计算C02-10R(6)泵浦条件下，不同工作气压、泵浦功率、腔长、输 出功率反射系数和输入功率反射系数等工作条件下的P支跃迁和Q支跃迁的输出 光强，总结不同工作条件对模式跃迁的影响机制。实验上，采用TEA-C0。激光器 和远红外法布里一珀罗干涉计测量10R(6)泵浦亚毫米波激光器的输出光强，验 证了P支和Q支跃迁的一般机制。以上的研究成果有助于深入了解光泵亚毫米波 激光器的物理机制和研制小型驱毫米波激光器，在～定的程度上也增强了亚毫米 波激光器的实用性。 关键字：亚毫米波，远红外激光，模式竞争 Tine Tine Mode Competition in Optically Pumped NH3 Sub．Millimeter Wave Laser Major Radio Physics Name Chen Weibin Suvervisor Profi Luo Xizhang AB STRACT In this paper．based on the theory of semi，elassical density matrix，studies on the mode competition in optically pumped NH3 sub-millimeter wave laser(SMMWL)． The gain coefficients of laser media in four energy-level system were deduced．Under the condition of COz·1 OR(6)Pumped，the output powers of Branch P transition and Branch Q transition were calculated by means of ireration method and numerical calculation under dlfferent operating conditions，including operating gas pressure， pumped power,the length of cavity，reflectance of output power and reflectance of input power and SO on．The rules of model transition under different operating conditions were summarized．In experiment，the output power of 10R f∞pumped SMMWL was measured、by TEA—C02 laser and far-infrared Fabry．Perot intefferometer．So the rules of Branch P and Branch Q transition were tested．The above studied results were useful for understanding the physical mechanism of optically pumped SMMWL in detail and producing miniature SMMWL．which will boost up the practicabilitv Of SMMWL to a certain extent． Key Words：Sub—Millimeter Wave(SMMW)，Far-infrared laser(FIRL)， Mode competition 2 第1章前言远红外(FIR—far 第1章前言 远红外(FIR—far i nfrared)或称亚毫米波(SMMW—submi儿imeter waves) 一般指波长范围是30 it m～2mm的一个电磁波谱窗口，实际上是指同一波段”1。从 远红外的历史发展角度来看，由于麦克斯韦经典电磁理论的确立，电磁波谱的研 究迅速从微波向短波长的方向发展，电磁波工作者称之为亚毫米波：同时光学技 术的研究对象(从红外到T射线)都得到了深入广泛的研究，也得到了广泛的应 用，从事光学研究的入就把红外向波长长的自然延伸部分称为远红外。实际上只 是术语表达的不同而[21。在本论