小型光泵腔式NH3分子亚毫米波激光器的实验研究

实验上采用金属网栅耦合的小型Ｆ－Ｐ腔式ＮＨ３分子激光器,用ＴＥＡ－ＣＯ２激光器的１０Ｒ（８）谱线作为泵浦,获得了２８１μｍ的亚毫米激光,并对该激光器工作参数的优化进行了系统的实验研究。     

甲醇远红外激光的一条新谱线

甲醇（ＣＨ３ＯＨ）分子是常用的ＦＩＲ激活介质,具有很特别的光谱特征。而小型光泵脉冲亚毫米波激光器是近年来才发展起来的新技术,作者已经成功地研制出管长为１０￣３０ｃｍ的ＣＨ３ＯＨＦＩＲ激光器,并获得谱线。本文利用ＣＨ３ＯＨ分子有表编制成数据库管理程序,对光泵ＣＨ３ＯＨ亚毫米波激光进行计算。代入ＣＯ２－９Ｐ（１６）线振动吸收跃迁的条件及相应的亚毫米波纯转动跃迁所受的跃迁选择条件,将泵频偏限制在±０．０     

光泵亚毫米波激光的喇曼过程相互作用

在小型光泵ＮＨ３分子亚毫米波激光器中，喇曼过程的相互作用变成一个重要的效应，它直接影响了激光器的输出强度和频谱特性。用大功率ＣＯ２－９Ｒ（１６）谱线泵浦ＮＨ３分子时，两个喇曼过程ｓ→ａＰ（７，０）和ｓ→ａＰ（７，１）相互作用导致彼此增强；而当ＣＯ２－９Ｒ（３０）谱线泵浦时，出现多个喇曼过程相互竞争的现象。     

光泵NH3分子远红外激光的一条新谱线

利用反射光栅调谐的脉冲ＴＥＡＣＯ２激光１０Ｒ（６）泵浦０．２ｍ长的小型ＮＨ３分子远红外激光器，当泵浦能量为１．１Ｊ，ＮＨ３分子气压为０．９ｋＰａ时，产生２９８μｍ的新谱线，对应Ｖ２：ａＲ（０，０），受激喇曼跃迁。     

栅网耦合的光泵腔式亚毫米波激光器及最佳工作气压研究

采用电感性金属网栅作为光学谐振腔的反射镜和输入输出耦合器 ,设计制作了长度分别为 10 0cm、2 0 cm和 10 cm的 Fabry- Perot腔式亚毫米波激光器。运用半经典密度矩阵理论 ,通过迭代法计算了光泵腔式 NH3分子亚毫米波激光器的最佳工作气压。在实验上测量了 TEA CO2 - 10 R(8)和 9R(16 )泵浦上述 NH3分子亚毫米波激光器的最佳工作气压。理论计算与实验结果一致。     

发射蓝光的光泵InGaN垂直腔面发射激光器

在１９９９年５月举行的激光电光学会议（巴尔的摩）的逾期论文中,日本东京大学和德国维尔兹堡大学的研究人员报导了室温下从光泵垂直腔面发射激光器（ＶＣＳＥＬ）二维列阵中获得蓝光发射（３９９ｎｍ波长）的成果。这种器件的列阵可望大大降低高密度光学存储器的读出时间。列阵中每一柱形氮化铟镓垂直腔面发射激光器的直径为１８μｍ,器件的间距为２２μｍ。这种激光器用氮激光抽运的３Ｈｚ重复频率染料激光器的３６７ｎｍ波长抽运,激光器的阈值抽运能量为１０ｍＪ／ｃｍ２或片载流子密度为２～４×１０１２ｃｍ２。该器件以多层结构形…     

小型光系NH_3分子气体远红外激光实验

本文详细介绍最有希望的远红外信号源—光泵远红外激光器（ＯＰＦＩＲＬ）实验系统，并改进了以往的检测方法，同时对ＮＨ_３分子２９２×１０（－６）米的超辐射激光谱线进行了实验研究。     

小型光泵腔式亚毫米波激光器工作参数的理论计算

采用半红典密度矩阵理论并运用迭代法对小型光泵腔式ＮＨ３分子亚毫米波激光器的工作气压,输入输出网栅的功率反射系数等工作参数进行了系统的理论计算,得到了该类激光器工作参数优化的一些规律。     

光泵远红外激光AC Stark分裂的频谱特性

利用三能级近似和多组三能级近似模型的光泵远红外激光增益解析表达式，通过迭代运算得到了ＣＯ２－１０Ｒ（８）泵浦ＮＨ３分子远红外激光的工作气压与输出光强的关系曲线和ＡＣＳ６ａｒｋ分裂的频谱曲线，以及最佳工作气压的理论值。     

二种单频自稳频高输出功率的长腔He－Ne激光器

作者用高气压加纵向非均匀磁场获得了二种单频自稳频高输出功率的长腔Ｈｅ－Ｎｅ激光器，其相干长度均大于１４ｍ，１ｍ放电管长（腔长为１１４０ｍｍ）单频激光器功率输出为１８～２５ｍＷ，在没有采取任何稳频措施的情况下，用这种激光器与碘稳定的Ｈｅ－Ｎｅ激光器拍频，经计算机自动采样，并进行阿仑方差（ＡｌｌａｎＶａｒｉａｎｃｅ）处理，测得其频率非稳定度为６．１７５×１Ｏ￣（－９）（≤１０ｓ）和３．３８×１０￣（－９）（≤１ｓ）．１．８ｍ放电管长（腔长为１９００ｍｍ）单频激光器功率输出为４０～５０ｍＷ，用测ｌｍ激光器同样的方法，亦在没有采用任何外加稳频措施的情况下，测得频率非稳定度为１．１×１Ｏ￣（－８）（ｒ≤１ｓ）和２×１０￣（－８）（≤１０ｓ），所有测试数据由中国计量科学院测定。     

Study on spectral characteristics and operating parameters ofoptically pumped NH3 FIR cavity laser

By solving the density matrix equations of a quantum system and taking into account the multibeam interference characteristics of a Fabry-Perot cavity, the output power density of an optically pumped NH ₃ far-infrared (FIR) cavity laser was calculated by means of the iteration method. Based on the calculations, the spectral characteristics and operating parameters of the laser were studied. Experimentally, by using inductive metallic meshes as reflectors and couplers, a series of FIR cavity lasers with a sample tube of 10, 20, and 100 cm in length were designed and constructed, and the emissions of the NH₃ cavity lasers pumped by a TEA-CO₂ laser with a 10R(8) or 9R(16) line were measured. The experimental results were in good agreement with theoretical calculations     

光泵NH3分子亚毫米波频谱特性的理论计算

本文从密度矩阵方程出发,分别采用三能级和多组独立三能级迭加的近似方法对光泵NH_3分子亚毫米激光器的输出光强进行了理论研究.同时根据NH_3分子能级结构对TEA-CO_2激光器的10R(6)谱线泵浦NH_3分子亚毫米波频谱特性进行了数值计算,理论计算结果与实验符合较好.     

Experimental Study of Pulsed Optically Pumped Superradiant and Cavity NH3 Far-Infrared Laser

Using a grating tuned TEA-CO2 laser with 10R(8) and 9R(16) line to pumped superradiant NH3 far-infrared (FIR) laser which operated in the mode of amplified stimulated emission and Fabry-Perot cavity NH3 FIR laser with a sample tube of 100cm and 20cm in length respectively, the corresponding pulsed FIR lasers were obtained successfully. Meantime, the experimental measure method was improved. Besides, the operating performance and the spectral characteristics of superradiant and cavity NH3-OPFIRL were studied experimentally.     

Very low threshold current densities (under 100 A/cm2) in AlGaAs/GaAs single-quantum-well GRINSCH lasers grown by molecular beam epitaxy

Threshold current densities as low as 80 A/cm2 for 3.3 mm-long cavity lasers, and 93 A/cm2 for 520 ?m-long cavity lasers have been obtained in AlGaAs/GaAs graded-index separate-confinement heterostructure (GRINSCH) single-quantum-well lasers with quantum-well widths between 65?165 A grown by molecular beam epitaxy. The structures were prepared on (100) GaAs substrates and do not display the earlier reported dependence of lasing threshold characteristics on the quantum-well thickness in the range studied (65?165 A).     

Operating Parameters Optimization of Miniature Optically Pumped Cavity NH3 Submillimeter Wave Laser

By means of the iteration method, the output power density of the miniature optically pumped NH₃ submillimeter wave (SMMW) laser was calculated based on the density matrix equations of a quantum system. Optimization of operating parameters including operating gas pressure, reflection coefficients of input and output meshes of the laser were studied systematically. In the paper, the concepts of the average activated length and the synthetical optimum value were defined, and some rules of the optimization were explained successfully. Experimentally, a cavity NH₃ SMMW laser that was composed of a pair of inductive metallic meshes and pumped by TEA-CO₂ 10R(8) line was used. The experimental results were in good agreement with our theoretical calculations.     

分子束外延生长高应变单量子阱激光器

采用分子束外延方法研究了高应变InGaAs/GaAs量子阱的生长技术.将InGaAs/GaAs量子阱的室温光致发光波长拓展至1160nm,其光致发光峰半峰宽只有22meV.研制出1120nm室温连续工作的InGaAs/GaAs单量子阱激光器.对于100μm条宽和800μm腔长的激光器,最大线性输出功率达到200mW,斜率效率达到0.84mW/mA,最低阈值电流密度为450A/cm2,特征温度达到90K.     

1.27 /spl mu/m metamorphic InGaAs quantum well lasers on GaAs substrates

Pulsed operation at a wavelength of 1.27 /spl mu/m from metamorphic ridge-waveguide (RWG) InGaAs quantum well lasers on GaAs substrates using an alloy graded buffer, grown by molecular beam epitaxy, is demonstrated. Laser performance is anisotropic along the two orthogonal <1/spl plusmn/10> directions with lower threshold currents along the <1-10> direction. Post-growth rapid thermal annealing further reduces threshold currents. For 4 /spl mu/m-wide RWG lasers, minimum threshold current densities are 1-2.5 kA/cm/sup 2/ for cavity lengths 0.6-1.5 mm.     

Comparison Between Single-Longitudinal-Mode and Two-Longitudinal-Mode Pumping Cavity OPSMMWL

A CO₂ infrared laser system with a etalon to be the longitudinal mode select equipment was set up to be the optically pump source, as well as a mini NH3 with 20cm long sample tube to be the sub-millimeter wave laser. CO2-9R(16) line was chose to pump the mini-NH3 SMMW laser, and 90.4um SMMW line was obtained by single-longtudinal-mode or two-longitudinal-mode pumping. Experimental comparison of output power and operating gas pressure between single and two-longitudinal-mode OPSMMWL were studied. It was found that the two-longitudinal-mode OPSMMWL could get higher output power and broader spectrum, existed a lower operating gas pressure and wider range of operating gas pressure. These experimental results verified the theoretical calculations before.     

The tuning characteristics of optically pumped fir cavity laser

Based on the quantum mechanics theory of density matrix and the principle of multiple-beam interference, the tuning characteristics of optically pumped NH₃ FIR lasers were studied. A series of metallic mesh Fabry-Perot cavity lasers with sample tubes of 10cm, 20cm and 100cm in length were constructed and operated successfully, and the FIR laser spectra of the NH₃ cavity lasers pumped by a TEA-CO₂ laser were measured.     

Room temperature continuous-wave operation of buried ridge stripe lasers using InAs-InP (100) quantum dots as active core

Self-organized InAs quantum-dot (QD) lasers emitting at 1.5 /spl mu/m were grown by gas source molecular beam epitaxy on (100) InP substrates. Room temperature continuous-wave (CW) operation of QD-based buried ridge stripe lasers is reported. We investigated experimentally the relevant CW performances of as-cleaved InP-based QD lasers for telecom applications such as temperature properties (T/sub 0/=56 K), infinite length threshold current density (J/sub /spl infin///spl sim/150 A/cm/sup 2/ per QDs layer) and internal efficiency (0.37 W/A). Lasing in pulsed mode is observed for cavity length as short as 200 /spl mu/m with a threshold current of about 37 mA, demonstrating the high gain of the QD's active core. In addition, the Henry parameter of these InP-based QD lasers is experimentally determined using the Hakki-Paoli method (/spl alpha//sub H//spl sim/2.2).