NaCl(OH-):(F2+)H色心激光的研究

文中报道了低温红外连续NaCl(OH-):(F2+)H色心激光的研究结果。当泵浦功率为4.5W,辅助光功率为34.5mW时,输出功率大于250mW,峰值波长为1.57μm。为保证色心激光稳定运转,必须要有辅助光。     

掺OH~－稳定的F_2~＋型心的激光振荡

利用我研制的掺质均匀、色心稳定性好的ＮａＣｌ（ＯＨ~－）：（Ｆ）＿Ｈ和ＫＣｌ（Ｎａ~＋，ＯＨ~－）：（Ｆ）＿（ＡＨ）色心晶体，我们实现了＞２５０ｍＷ的１．５７μｍ和＞４０ｍＷ的１．８８μｍ色心激光输出。本文报道其实验结果。     

横向泵浦室温氟化钾镁晶体色心激光器

利用横向泵浦腔体实现氟化钾镁晶体色心室温稳定激光器运行，用氮分子激光泵浦的染料激光为泵浦源，单脉冲色心激光输出能量为0.22mj，光-光能量转换效率为7.3%，激发阈值为0.5mJ。色心激光束发射角为3.0mrad，偏振度为0.99。色心激光输出波长从703nm至800nm，中心波长位地755nm。     

掺OH^—稳定的F^＋2型心的激光振荡

利用我所研制的掺质均匀、色心稳定性好的ＮａＣｌ（ＯＨ＾－）：（Ｆ＾＋２）Ｈ和ＫＣｌ（Ｎａ＾＋，ＯＨ＾－）：（Ｆ＾＋２）ＡＨ色心晶体，我们实现了＞２５０ｍＷ的１．５７μｍ和＞４０ｍＷ的１．８８μｍ色心激光输出。本文报道其实验结果。     

NaCl（OH^—）：（F2^＋）H晶体的制备及红外色心激光运转

报道了NaCl(OH~-):(F_2~+)_H色心晶体的制备、晶体的光学表面加工、色心激光运转等关键问题;讨论了色心激光输出功率与辅助光的关系;成功地实现了中心波长为1.57μm的红外NaCl(OH~-):(F_2~+)_H色心激光的运转。     

LiF晶体中F+,/sup>2色心在室温下的激光运转及可调谐输出

本文把纯LiF晶体中色心激光宽带输出的转换效率提高到11%，得到了心激光的宽带输出与温度的变化曲线。实现了色心激光的波长从0.86～1.02 μm的可调谐输出，并对泵浦光作用下LiF晶体中的各种色心动力学机制进行了分析。     

岩盐晶体用电场激发时产生激光振荡的可能性

碱卤晶体中色心的激光振荡开拓了在近红外光谱区获得有效的可调谐光源，并在可见和紫外光谱区建立这种光源的可能性。所有现存的色心激光器都是使用光泵激发的，一般使用气体离子激光器的辐射激发。如果能够用电泵浦直接激发，色心激光器的紧凑性将得到相当大的改善。     

NaCl（OH￣－或O￣－＿2）：（F￣＋＿2）＿H色心激光研究的进展

文中介绍了近几年来ＮａＣｌ（ＯＨ~－或）：色心激光研究的进展，简要说明了它的应用前景。     

LiF晶体中F_2~＋色心在室温下的激光运转及可调谐输出

本文把纯ＬｉＦ晶体中色心激光宽带输出的转换效率提高到１１％，得到了心激光的宽带输出与温度的变化曲线。实现了色心激光的波长从０．８６～１．０２μｍ的可调谐输出，并对泵浦光作用下ＬｉＦ晶体中的各种色心动力学机制进行了分析。     

YAG：Nd晶体色心及其对激光性能的影响

本文在整理有关实验咸实的基础上综述了ＹＡＧ：Ｎｄ晶体色心的形成，光谱特征及其对激光性能的影响，提出了防止色心形成的措施。     

Electrical pumping of color center lasers

This paper presents an assessment of the feasibility of using electrical pumping to achieve laser action in color centers in the alkali halides. We discuss mainly the self-trapped exciton in the alkali halides, which is a prime candidate for such a pumping scheme because it is known to produce strong electroluminescence. The theory of electrical contacts to insulating crystals is reviewed, as is the theory of space-charge-limited currents in insulators. It is shown that sufficient energy can be delivered to an alkali halide crystal by a space-charge-limited current to reach the threshold for laser action. We present experimental evidence which demonstrates that when ohmic contact is made to a KI single crystal, large space-charge-limited currents can flow. Finally, from the measured value of the electroluminescent intensity we infer the value of the population inversion achieved through electrical pumping of KI with blocking contacts.     

Dynamic displacement anisotropy of atoms,streamer discharges and phonon focusing in BeO and CdSe crystals and I–VII compounds

Streamer discharges at 77 K and crytallographically oriented surface spark breakdown at 295 K have been obtained in BeO crystals. An inverted temperature dependence has been found for the breakdown anisotropy compared with that in CdSe crystals. It is shown that the temperature dependences of the excitation thresholds of the incomplete electric breakdown at different crystallographic orientations in dielectrics as well as those of the streamer discharges in hexagonal semiconductors are controlled by the anisotroply of ionic dynamic displacements. The directions of maximum phonon focusing have been calculated in the localoisation planes of the incomplete breakdown in NaCl, KBr and LiF crystals at room temperature in accordance with well-known breakdown model along phonon streams. It is shown that the alkali halide breakdown data do not agree with this model. An anisotropy is predicted of the dynamic displacement of atoms in alkali halide crystals as well as in the basis plane and mirrorsymmetric directions of planes containing the crystallographic c-axis in hexagonal II–VI compounds, which allows us to explain the observable particularities of the discharge anisotropy in both cubic and hexagonal crystals.     

KCl:Li FA(Ⅱ)色心激光晶体材料(综述)

本文以KCl:Li FA(Ⅱ)心为色心激光材料的代表,从材料物理化学的角度分析了KCl-LiCl以及与基质KCl有关的掺杂体系的性质,综述了掺Li+KClFA(Ⅱ)心的主要特性,总结色心激光晶体的制备.     

Yb:YAG激光晶体的高温退火和高浓度掺杂效应

测定了提拉法生长的不同掺杂浓度的Yb:YAG晶体从紫外到近红外区的吸收光谱,发现高温氧化气氛退火后原先可见光区色心宽带吸收消失的同时,在紫外区出现新的吸收带,并通过色心的转化对这一现象进行了解释.在紫外区和近红外区吸收光谱中,发现随掺杂浓度的升高220 nm和940 nm附近的吸收带的位置略有移动,提出是由于Yb3+离子掺杂引起的晶格结构畸变导致了Yb:YAG晶体光谱性质的改变.通过X射线衍射对不同掺杂浓度Yb:YAG晶体晶胞参数的测定,证实高的掺杂浓度导致Yb:YAG晶体发生较大的晶格畸变.在不同掺杂浓度Yb:YAG晶体的激光实验中,观察到Yb3+离子掺杂浓度影响晶体的激光性能.     

MgF2光窗性能与洁净工艺的研究

介绍了ＭｇＦ２晶体的主要物理性能。研究了它与其它碱土金属卤化物相比，更适合作为真空紫外窗口材料的理论依据。最后简要阐述了其用于整管制作时的洁净工艺。     

Excimer ions as possible candidates for VUV and XUV lasers

Optical transitions in ionic excimer molecules seem to be suitable candidates for lasers in the VUV and XUV region. Potential curves, transition wavelengths, radiative lifetimes, and cross sections for stimulated emission are calculated for several alkali halide ions. In addition, possible laser transitions in rare gas halide ions are briefly discussed.     

色心激光材料——掺杂KCl单晶的研制

用引上法生长了掺锂KCl色心激光晶体,获得尺寸为φ25×100毫米的单晶,晶体中锂原子的含量可控制在10~(-3)～10~(-2)％(重量比)之间。测定了三种掺杂KCl单晶X-射线辐照后的吸收光谱。     

碱卤晶体中F心的ESR研究

目前运转的色心激光器中使用的工作物质主要是碱卤晶体,“工作心”主要有F_2、F_2~ 、F_2~-以及杂质心等。这些色心几乎都是从F心演变而来的,因此F心是最基本的色心。由于F心是晶体中阴离子空位捕获一个电子,故它有顺磁性,可以用ESR方法去研究它的结构性质。 有关F心的ESR研究虽然国外早有许多报导,但在国内尚少见。本文介绍我们对KCl、NaCl、KBr、LiF几种碱卤晶体的F心ESR研究结果。     

红外可调谐NaCl(OH~-)∶(F_2~+)_H色心激光

采用我们研制的优质Nacl(OH~-)∶(F_2~+)_H色心晶体作激光介质,在X型激光腔中,实现了中心波长为1.57μm,可调谐波段为1.40～1.75μm的低温红外连续可调谐色心激光运转。探讨了(F_2~+)_H心的几个吸收带,激光输出与工作介质和辅助光的关系等问题。     

Room-temperature color center lasers

A survey of results is presented on the development of room-temperature tunable lasers using color centers in ionic crystals and on using color center crystals as nonlinear filters and passive Q switches for neodymium lasers