内腔式M_e~2＜1的CO_2激光器

本文报道一种等效光束质量因子Ｍ_ｅ~２＜１的ＣＯ_２激光器已研制成功，其束中心亮度比ＴＥＭ_００模的亮度高约３倍，发散角小２～３倍，输出功率与同尺寸多模激光器相比仅低５～１０％，得到了国际上首批超衍射极限输出的ＣＯ_２激光器。     

单光束双脉冲、双波长巨脉冲Cr:LiSAF激光器

为实现单光束、双波长、双脉冲Cr:LiSAF调Q激光输出,实验中创造性地采用高压方波驱动电光Q开关实现了双波长、双脉冲的Cr:LiSAF可调谐激光输出。获得了波长分别为890nm与900nm,脉冲能量分别为31mj与38mj,脉冲宽度分别为30ns和27ns,脉冲间隔82μs的单光束、双波长、双脉冲Cr:LiSAF调Q激光输出,双脉冲的不同轴度不大于0.15mrad。为差分吸收激光雷达系统所需单光束、双波长、双脉冲激光器的进一步研制奠定了良好的理论与实验基础。     

演示手持式绿光YAG激光器

去年十月在西雅图、华盛顿举行的美国光学学会光学和激光科学与技术会议上，A-B激光公司报告了用二极管抽运的YAG激光器。它以连续或脉冲方式运转，具有可调谐脉冲长度和波形。输出是衍射极限绿光光束，直径为0.9 mm。     

用棱镜扩束的窄谱宽染料激光器

对一种用棱镜作光腔内光束扩展器，用调Q激光抽运的脉冲染料激光器的光谱调谐性能进行了实验研究。实验证明，即使染料溶液不循环，该器件也可以每秒1次的重复率工作，染料激光振荡器的输出谱宽达到0．013埃,调谐范围达到350埃，无腔内F-P标准具时，输出功率约50千瓦。     

窄线宽可调谐的准分子激光振荡——放大系统

自由振荡的准分子激光一般具有1nm左右的线宽,而普通稳腔输出的激光光束质量较差,发散角约2～4mrad。在众多的准分子激光作用领域(非线性光学,激光光谱、激光蚀刻、激光医学、激光大气测量和激光加工等等)、对准分子激光的光谱特性、光束质量提出了越来越高的要求。 我们设计了一台窄线宽、可调谐的准分子激光     

ArF准分子激光器的窄线宽可调谐运转及注入放大

在一台快放电泵浦的ＡｒＦ准分子激光振荡放大系统的振荡级上采用光栅、扩束镜、光阑等腔内元件，用组合输出镜获得了线宽小于０．１ｎｍ，调谐范围～１ｎｍ的激光输出。注入到非稳腔结构的放大级，注入后放大级效率提高了约５０％，获得了平均３０ｍＪ／脉冲的高光束质量的窄线宽可调谐激光，最大单脉冲能量＞５０ｍＪ，并进行了氧气的吸收光谱实验。     

飞秒激光行波泵浦BBO晶体光参量放大

采用飞秒钛宝石激光放大器二次谐波为泵浦源，行波泵浦ＢＢＯ晶体光参量放大器，获得了可调谐输出（０．４４～２．６μｍ），最大输出能量约４０μＪ／脉冲，测量了参量激光的调谐特性、能量分布和线宽，理论与实验符合较好。     

钛宝石激光器的多模式运转

在一台双光束泵浦的钛宝石激光器中实现了可调谐连续输出、独立自锁模、交叉锁模和多脉冲模运转式。分析了可调谐连续输出模式下两个激光腔的增益竞争,研究了飞秒和皮秒激光腔内的群速弥散、自相位调制、交叉相位调制以及自振幅调制。结果表明,可调谐连续输出模式下两个激光腔的输出主要取决于泵浦激光的功率,独立自锁模工作模式下,群速弥散和自相位调制决定了自锁模的稳定性;交叉锁模工作模式下,交叉相位调制是影响飞秒和皮秒脉冲之间同步性的主要因素。多脉冲工作模式下,脉冲自相关曲线的测量结果表明,飞秒脉冲仍然是单脉冲,而皮秒脉冲分裂为3个次脉冲。     

同时产生红、绿、蓝光输出的单晶

西班牙马德里自治大学的研究人员研制出一种运转在基波为１３３８ｎｍ的掺钕四硼酸钇铝（Ｎｄ：ＹＡｌ_３（ＢＯ_３）_４）单晶体,可产生红色、绿色和蓝色的激光辐射．对基波倍频可获得红光（６９９ｎｍ）,以可调谐钛宝石泵浦的８０７ｎｍ和７５５ｎｍ激光,分别与基波?..     

宽调谐(红外-紫外)高功率脉冲激光系统研制成功

宽调谐(红外-紫外)高功率脉冲激光系统是国家七五科技攻关项目,由浙江大学光仪系负责研制,1990年研制成功,并于1990年12月9日由12名专家组成的鉴定委员会通过了技术鉴定。 该激光系统的调谐范围很宽(199.6nm至4.8μm),整个系统采用微机控制谐波发生器的匹配角自动校正,染料激光器波长自动扫描、紫外扩展器的波长自动跟踪及输出光束自动找准。激光系统最大可调谐输     

激光波长对SOI激光结晶机理的影响

本文用两种波长不同的激光——Ar~+激光和CO_2激光,对以石英为衬底的a-Si SOI进行了激光结晶。两者的结晶机理不同,得到了不同的结晶形貌。     

Measurement of nitrogen laser channel current, inductance, and resistance

The laser channel current, inductance, and resistance of a nitrogen laser have been measured using a magnetic probe and have been found to have values of ∼42 kA, 1.6 nH, and 0.1 Ω, respectively, for a laser channel gap of 1.6 cm operated at 10 kV and 60 torr. The results of the measurement confirm a double discharge mechanism for the nitrogen laser.     

激光相干合成的研究进展:2011—2020

本文回顾了过去10年激光相干合成领域取得的重要进展,总结了可合成激光模块性能提升的标志性成果,梳理了相干合成使能技术取得的重要突破,展示了不同类型激光相干合成取得的成果及其多样化应用,并对激光相干合成领域的发展进行了展望。     

Direct measurement of the frequency-modulation characteristics of a coupled-cavity laser

The modulation characteristics of a coupled-cavity AlGaAs injection laser have been investigated in the frequency range 0.2 to 1.0 GHz. The laser operates in a single longitudinal mode for almost all injection currents and modulation indices above laser threshold. The phase and amplitude of the current-to-frequency-modulation transfer function of the laser have been measured.     

激光相变硬化工艺参数的研究

本文报导了用HJ-1型CO_2激光器对六种金属材料进行的相变硬化实验结果.研究了激光工艺参数对材料硬化层组织与性能影响.提出这些材料激光相变硬化的最佳工艺参数;并将激光硬化V型导轨的实验结果和普通热处理结果作比较.     

激光对非λ/4膜系变反射率薄膜的损伤机理

讨论了高功率激光对非λ/4膜层组成的变反射率光学介质薄膜损伤时的场作用和热作用的物理机理,并对实际膜层的激光损伤阈值进行了测试.理论和实验研究结果证明,激光对该种膜系产生损伤的主要原因是膜层吸收激光能量引起的.     

Breakdown and self-focusing effects in gases produced by means of a single-mode ruby laser

Using a passivelyQ-switched ruby laser, operating in a single axial and transverse mode, sparks produced in a number of gases at pressures ranging from 760 to 9000 mmHg have been studied. Breakdown threshold measurements for both single and multimode laser radiation have been made and in addition, the characteristics of the sparks produced with single-mode radiation have been investigated. Photography at 90° of the scattered laser light showed the existence of scattering regions with transverse dimensions not exceeding the 5-μ resolution of the optical system. Furthermore, a large amount of laser light is scattered in the forward direction. The intensity, angular distribution, and spectral characteristics of this scattered radiation have been determined. Various possible mechanisms that could account for these phenomena are discussed, and it is concluded that self-focusing of the laser beam after the initiation of the breakdown process may be occurring.     

Amplified spontaneous emission in narrow-band pulsed dye laser oscillators--Theory and experiment

We have investigated the effect of amplified spontaneous emission (ASE) on the spectral and temporal characteristics of narrow-band pulsed dye laser oscillators. The space and time dependent rate equations for the molecular populations and photon fluxes have been solved numerically to study the dependence of ASE on various laser parameters and the effects of ASE on the spectral and temporal profile of the dye laser output. To account for the diffraction losses present in a real dye laser oscillator, appropriate feedback factors for the laser and ASE photon fluxes were introduced into the boundary conditions for the oscillator. These theoretical results have been substantiated by experimental measurements of ASE in a narrow-band pulsed dye laser oscillator. We show that a considerable reduction of ASE in a grazing incidence grating dye laser oscillator can be obtained by appropriately shaping the pump pulse. Oscillations observed in the temporal output of pulsed dye lasers are also discussed.     

Temporal coherence properties of picosecond pulses generated by GaAlAs semiconductor lasers for directly modulated and frequency stabilized optical communication systems

The temporal coherence properties of picosecond pulses from GaAlAs semiconductor lasers have been studied by measuring first- and second-order autocorrelation functions with a Michelson interferometer. The time-bandwidth product and chirp have been evaluated for several different laser structures and frequency stabilization schemes. Time-bandwidth products from 1.2 for a CSP laser to 3.6 for a TJS laser were obtained with operating conditions representative of high-speed communication systems. Computer simulations based on the rate equations have been used to model the temporal coherence during the pulse and they show good agreement with our measurements. The results show that it is important to select the appropriate laser structure and stabilization scheme in applications where the temporal coherence is significant for system performance.     

Theoretic model of myocardial revascularization by far infrared laser and experimental validation

A theoretic model of myocardial revascularization by a far infrared laser has been established and a quantificational rela- tionship between the aperture of laser channel and parameters of laser has been concluded according to thermodynamics and the law of interaction of far infrared laser and myocardium. The experiment of a carbon dioxide laser revascularization in porcine myocardium has been done for different laser powers and irradiation time. The relative errors between experi- mental result and theoret...