激光应用与全息术和光学信息处理

0608761双向光泵浦XeF(C-A)激光〔刊,中〕/于力//强激光与粒子束.—2005,17(12).—1765-1768(E)讨论了双向光泵浦XeF(C-A)激光技术,给出了双向泵浦情况下的XeF2光解离波图像。在双向泵浦条件下XeF(C-A)激光输出能量提高了近3倍,最大输出达到3.3J,激光脉宽增加到1100ns。激光输出特性受XeF2初始浓度的显著影响,激光形成时间随XeF2初始浓度增大而加长,激光脉宽先增大后减小,激光近场光斑呈现出不同的形状,由方形变化为“X”形状。参90608762近地大气532nm激光散射的实验与计算〔刊,中〕/狄凌峰//量子电子学报.—2005,22(6).—960-964…     

光抽运XeF(C-A)蓝绿激光器

利用分段表面放电作为光抽运源 ,采用光解离XeF2 技术 ,研制了一台 XeF(C A) 蓝绿激光器。抽运源有效激活长度为 6 0cm ,单位长度的沉积功率为 4 5MW /cm。在 2 5 0PaXeF2 / 6 0kPaAr/ 40kPaN2 条件下 ,采用平凹腔 ,输出耦合为 4% ,获得了XeF(C A)激光输出。对XeF(C A)激光特性参数进行了测量 ,输出能量为百毫焦耳量级 ,最大能量达 16 7mJ,激光脉宽～ 6 0 0ns ,辐射光谱范围 470～ 5 0 0nm ,发散角水平方向为 1 7mrad ,垂直方向为3 7mrad。     

电子束泵浦XeF准分子激光

本文介绍用强流脉冲电子束横向泵浦 XeF 准分子激光的初步实验,在 Ar:Xe:F_2=97.2:2.5:0.3混合气体总气压为2.5大气压条件下,获得5.1焦耳激光输出能量。     

用于抽运XeF(C-A)激光的分段表面放电辐射源

研制了用于抽运激光的分段表面放电辐射源。辐射源采用分段表面滑闪放电诱导长距离、线性等离子体通道大电流放电 ,实现了高亮度真空紫外辐射 (140～ 170nm) ,且各段总的放电分散时间小于 10 0ns。用该辐射源解离XeF2 获得了XeF (C A)激光输出     

Nd:P5O14的XeF准分子泵浦

我们报导了第一台准分子(XeF)激光泵浦五磷酸基质中Nd3+的激光器。3530埃的XeF激光输出被Nd3+离子的4I9/2→4D3/2跃迁所吸收，结果在4F3/2的跃迁上产生1.05微米的激光输出。对一个振荡器结构泵浦，阈值能量只有3亳焦耳，而斜率效率近1%。瞬时输出约为6.6亳徵秒（半极大全宽度）宽度的单脉冲，它起因于短的泵浦脉冲（半全宽≈24亳微秒）和Nd:P5O14高增益。这个装置可用来产生1~10亳微秒的短脉冲而不需要通常闪光灯泵浦激光器中的Q开关。     

面预电离F原子激光和XeF准分子激光实验研究

本文报道了面预电离F原子激光和XeF激光输出能量以及F原子激光光斑随各气体分压的变化情况。在适当的气体混合物中放电获得了F原子和XeF准分子激光充满放电截面的完整光斑，取得了满意预电离效果。获得了F原子623．9nm、634．8nm、712．8nm和731．1nm四波长激光同时振荡以及F原子激光和XeF激光同时振荡，并作了定性分析。     

XeF激光器光泵技术的改进

苏联列别捷夫物理研究所采用光学泵浦方法，已在XeF中得到1%的效率和28 J的脉冲能量。V. S.朱耶夫等人用开放式大电流放电所产生的真空紫外光录浦XeF,观测到353和385 nm的激光发射。     

蓝绿XeF系统达到6焦耳的创记录输出

加利福尼亚门洛帕克国际空间研究所的研究者们从一个光解泵浦的氟化氙激光器中已经获得了创记录的6焦耳输出，波长在483毫微米处。与较普通的XeF激光器不同，它在B→X跃迁上产生350毫微米的紫外激光，而蓝绿的XeF系统通过C→A跃迁而运转，所产生的波长在455和525毫微米之间。这种在蓝绿区可调的高能激光发射对水下潜艇的激光通信线路是重要的，这也是国防部正在积极从事的一项应用研究。     

XeF激光器中XeF2气体的监测

给出了一种用吸收光谱法实时监测XeF激光器中XeF2气体压强的方法,标定了XeF2气体在波长为253.7nm处的吸收截面的大小Ó2253.27XeF=(1.55±0.05)×10-19cm2.用该监测系统测量了XeF2气体与3种作为激光器气室材料的反应速率,同时研究了XeF蓝绿激光器中输出激光能量与XeF2气体压强的关系.     

电子束泵浦异核型XeF准分子激光器的实验研究

本文报导了一种用电子束泵浦的紫外XeF准分子激光器。它采用长刀片阴极这种简便的方法获得了高密度的矩形截面电子束,成功地泵浦了工作物质。     

A 170 J electron beam pumped XeF(C→A) laser

A pulse output energy of 170 J has been achieved from an XeF(C→A) laser system, pumped by a pair of counterpropagating, three-meter-long electron beams. This represents a record for all types of pumping, for this excimer system. Energy was extracted from a volume of ~100 L, using a free-running stable oscillator. No evidence of laser oscillations on the competing XeF(B→X) transition was observed. Within the extraction volume the laser gas was pumped at a rate of 140 kW/cm³ (time average value), for a period of 1.7 μs. The optical cavity was folded, giving a gain length of 6 m. The optical pulse duration was 0.8 μs (full width at half maximum), and the observed flux buildup time of ~1 μs was consistent with modeling and a measurement of the net gain. The specific output energy was 1.7 J/L which is comparable to that achieved in previous, small scale experiments at somewhat higher pump rate. The results confirm the volumetric scalability of the electron beam pumped XeF(C→A) laser system to high output energy per pulse, and the feasibility of operating this system at a low electron beam pump rate which relaxes constraints on the design of the electron gun and pulse power subsystems in a high output energy device. Means for extending the laser pulse duration and increasing the output energy of the specific test device are discussed. An output energy of ~1000 J is projected for an optimized gas cell width, for full size resonator mirrors, and with injection     

2-kHz repetition rate XeF laser

High-repetition-rate laser action, up to 2 kHz, has been demonstrated in XeF molecules at 351 and 353 nm by using a blowdown fast transverse-flow system and a four-circuit, thyratron-switched, low inductance pulse generator. For a typical run, the transverse flow was uniform, and the average flow velocity was 25 m/s across a discharge region of1.4 times 0.4 times 30cm³. The gas mixture used was He:Xe:NF3= 100:1.5:0.5, and the total pressure was varied from 600-1200 torr. For single-pulse operation, the maximum laser output energy was 22 mJ/pulse, and the electric efficiency was 0.4 percent. For a 2-kHz repetition rate, the average laser output energy was approximately 12 mJ/pulse with 50 percent variations. Hence, an average output power of 24 W was obtained.     

25kHz、约2ns声光调Q Nd:YVO4激光器研究

为了获得高重频窄脉冲高光束质量激光输出,采用LD抽运Nd:YVO₄晶体声光调Q方案,进行了相关理论分析和实验验证,振荡级获得了重频25kHz、单脉冲能量22.4μJ、脉冲宽度2.19ns、光束质量因子M2 < 1.2的种子激光,光光转换效率为24.3%;放大级获得了重频25kHz、单脉冲能量585μJ、脉冲宽度2.26ns、光束质量因子M2 < 1.7的激光输出,提取效率为15.6%。结果表明,采用LD抽运Nd:YVO₄晶体声光调Q方案能够获得高重频、窄脉冲、高光束质量激光输出,其实验现象与理论计算结果较为符合。     

Maximum performance of discharge-pumped exciplex laser atλ=222 nm

The results of an experimental investigation into lasing and spontaneous emission from Ne(He, Ar)-Kr-HCl are presented. Evidence has been gathered of the effect of the pumping power, preionization rate, pumping pulse duration, and composition and pressure of the gas mixture on the lasing characteristics under discharge pumping. KrCl* formation efficiency is shown to be nearly half as much as for XeCl*. The output energy was 0.65 J for ~60 ns laser pulse duration (FWHM), 2.5% efficiency based on the pumping power, and 0.65% efficiency based on the stored energy while for the 10 ns pulse duration, 2.7% efficiency based on the pumping power and 0.8% efficiency based on the stored energy the output energy was 0.15 J. Recommendations are made for development of KrCl lasers with maximum output parameters     

CuBr Laser Excited by a Capacitively Coupled Longitudinal Discharge

The paper presents the study of the CuBr laser energy characteristics using capacitively coupled discharge excitation. We have studied the effect of the addition of HBr on laser performance for gas discharge tubes of different bore diameter at various input power conditions. When adding HBr pulse and average output power as well as laser efficiency more than double increase due to the shortening of the current pulse rising time and its duration. The total maximum average lasing power of 3.7 W was obtained at 0.27% efficiency. In the paper, we also notice that when adding admixtures capacitively coupled discharge pumping is superior to traditional glow discharge pumping.     

高斯镜参数对LD泵浦Nd:YAG激光器的影响

实验研究了输出镜为不同参数高斯镜时,偏心对LD泵浦Nd:YAG激光器的影响及激光器的输出特性。仅当光轴与激光晶体中心轴、Q开关中心轴一致,且经过高斯镜反射率中心时,可同时实现最大能量、最窄脉冲宽度和最小发散角输出。存在偏心时,高斯镜反射率半径越小或中心反射率越大,则能量下降越多,脉冲宽度和发散角增大越大。对于反射率半径为2.5 mm和中心反射率为30%的高斯输出镜,偏心0.5 mm时,能量降低7%,脉冲宽度增宽33%,发散角增大20%。激光性能方面,高斯镜反射率半径越小或中心反射率越小,光束质量越好,但效率低。综合考虑偏心影响和激光性能,反射率半径为2.75 mm和中心反射率为20%的高斯镜作为输出镜最佳。泵浦能量为984 mJ时,获得了能量128 mJ,脉冲宽度7.3 ns,光束质量M2因子约4.6的1064 nm激光输出,对应光光转换效率为13%。实验结果为激光器设计和装调提供了参考。     

放电激励重复频率HF激光器稳定输出实验研究

在放电激励重复频率气体激光研究中,激光器重复频率运行能量稳定输出是提高其输出平均功率及其实用化的基础。利用实验室已建立的单脉冲输出能量焦耳级的放电激励重复频率脉冲HF激光装置,通过调节气体介质循环速率及优化实验条件,开展激光器重复频率运行稳定输出实验研究,获得激光器重复频率运行时能量稳定输出的最佳工作条件。研究结果表明,随着运行频率的上升,激光输出能量衰减较快;增大气体介质循环速率有利于改善放电稳定性,提高激光器重复频率运行时输出能量稳定性。当混合气体工作介质以3.5m/s的流速循环时,激光器可实现1～50Hz重复频率激光输出,在重复频率50Hz运行时稳定输出能量约130mJ,能量波动约5%。     

信号光脉冲比抽运光窄12倍的内腔式KTP光参量振荡器

在闪光灯抽运的非稳腔Nd∶YAG被动调Q激光器腔内,放置非临界相位匹配KTP晶体,构成内腔式单谐振KTP光参量振荡器(OPO)。研究了输出信号光的波长调谐性能,获得1.57~1.60μm可调谐激光脉冲。实验结果表明,1.57μm信号光的输出能量随着光参量振荡器腔长的增加而减少,脉冲宽度随着腔长的增加而有所变化;抽运能量较大时,转换效率随着抽运能量的增加趋于饱和然后逐渐下降;对此给予了合理的理论解释。当光参量振荡器的腔长为5 cm,1.06μm抽运光脉冲宽度为30 ns时,输出的1.57μm信号光的脉冲宽度为2.5 ns,能量为21.3 mJ。1.57μm信号光的脉冲宽度仅为1.06μm抽运光脉冲的1/12,总的电光能量转换效率为0.128%。     

共掺Nd~（3＋）离子改善了Cr：ZnWO_4的激光效率

共接Ｎｄ３＋离子改善了Ｃｒ：ＺｎＷＯ４单晶质量，提高了激光效率。室温下用红宝石激光泵浦，在φ６×１９ｍｍ的晶棒中，获得０．９５μｍ的激光脉冲，最大输出能量达１．６２ｍＪ，泵浦斜率效率为０．７９％。     

封闭式高重复脉冲铜蒸气激光

一、引言 铜蒸气激光具有高增益、高功率和高效率等特点,受到普遍的注意。最初的铜蒸气激光是用纯铜在氧化铝管中加热到1500℃而产生铜蒸气作为工作物质的。人们为了降低工作温度,找到了卤化铜作为工作物质,使激光的运转温度在400℃至600℃,而激光的功率仍保持不变。卤化铜激光最初是采用双脉冲工作方式,第一个放电脉冲产生卤化铜的分解,第二个放电脉冲则使铜原子在电子碰撞下激发到激光上能级。1974年,双