基于泵浦控制的波长可调谐Er:YAG中红外脉冲激光

在腔内不添加任何调谐元器件,并且不改变输出耦合率的情况下,分析能级寿命和受激辐射截面,调控泵浦脉冲模式,实现同一台激光器中多种波长模式的输出。典型输出模式包括:2 699 nm激光(1.06 mJ)和2 803 nm激光(1.25 mJ)的单波长输出,2 699 nm(1.06 mJ)和2 803 nm(0.86 mJ)双波长激光的时间分离分频输出,2 699 nm(1.06 mJ)和2 830 nm(1.35 mJ)双波长激光的时间分离分频输出。本文研究有望成为测量有机物浓度的差分吸收雷达的光源,使单一探测器实现差分测量,同时大幅度简化差分吸收雷达的检测系统,降低成本。     

宽波段温度调谐MgO：LiNbO3光学参量振荡器

采用电光调Q脉冲Nd:YAG激光的二次谐波（532nm)抽运温度调谐的MgO:LiNbO3晶体光学参量振荡器,调谐范围达800nm-1750nm.在单谐振运转条件下,抽运阈值为21．5mJ/pulse,最大抽运能量为58mJ时输出为6．45mJ,在大信号情况下的能量转换效率达11％,输出线宽1nm左右。     

宽波段温度调谐MgO∶LiNbO3光学参量振荡器

采用电光调Q脉冲Nd∶YAG激光的二次谐波 (5 32nm)抽运温度调谐的MgO∶LiNbO3晶体光学参量振荡器 ,调谐范围达 80 0nm～ 175 0nm。在单谐振运转条件下 ,抽运阈值为 2 1.5mJ/ pulse ,最大抽运能量为 5 8mJ时输出为 6 .45mJ ,在大信号情况下的能量转换效率达 11% ,输出线宽 1nm左右。     

β-BaB2O4晶体中367.3—379.4nm的和频产生

用调谐的Rh·6G染料激光与Q-YAG激光在β-BaB₂O₄(BBO)晶体中和频,已获得367.3—379.4nm范围内连续可调谐输出,和频输出能量为2mJ,转换效率为12%,还讨论了非共线传播对和频输出能量及转换效率的影响。 关键词：     

水下探测用高重频双波段激光器

就水下探测设备要求激光器输出频率高、体积小、波段宽,提出通过侧面泵浦激光技术和电光调Q技术获得高重频1 064 nm波段激光。利用腔外波长变换技术,实现532 nm激光输出。在电源输入电流100 A,调Q驱动频率1 kHz的条件下, 获得36 mJ的1 064 nm激光输出和20 mJ的532 nm激光输出。试验结果表明:通过半导体泵浦技术和频率变换技术,可实现高重频窄脉宽双波段激光输出。     

全固态kHz啁啾脉冲飞秒激光放大器

要建造大功率超强激光系统,必须将nJ量级的种子进行放大,以得到mJ量级以及更高能量的激光输出.为达到这个目的,必须使种子能量指数增加,再生腔放大器是实现这一目的的良好途径;同时,为了得到更稳定的激光输出,须采用高重复频率的泵浦源.为此,设计了一种kHz重复频率激光泵浦的再生放大器,使用15 mJ的527 nm的绿光泵浦,得到了约2.3 mJ的800 nm放大激光输出,同时,对其输出激光的光谱特性进行了测量,将带宽为40 nm的种子注入后,得到了光谱带宽约为30 nm激光输出.     

532 nm激光辐照下ZnSe薄膜光学特性研究

采用电子束热蒸发技术制备了ZnSe薄膜,研究了532 nm波长的不同能量(2.0 mJ、2.5 mJ、3.0 mJ)、不同脉冲数(3、10、15)激光诱导前后,ZnSe薄膜的透射率、折射率、消光系数、损伤阈值(LIDT)的变迁。研究结果显示,在能量为2.0 mJ激光辐照后,ZnSe薄膜折射率提高,透射率下降。相比较能量为2.5 mJ、3.0 mJ激光辐照,在能量为2.0 mJ激光辐照后折射率提高最明显,由2.489 4提高到2.501 6。薄膜损伤阈值从0.99 J/cm2提高到1.39 J/cm2(10脉冲辐照);薄膜的损伤经过了无损伤到严重损伤突变的损伤演变过程。采用原子力显微镜对预处理后薄膜表面粗糙度进行检测,发现激光预处理后的薄膜表面粗糙度Ra有所下降,从0.563 nm降低到0.490 nm(15脉冲激光辐照)。     

宽带输出PM580掺杂聚甲基丙烯酸甲酯固体染料激光器研究

采用高效激光染料PM580作为掺杂物质,聚甲基丙烯酸甲酯(PMMA)作为基质,在对固体染料光谱特性研究的基础上,重点研究了调Q倍频Nd:YAG抽运下不同染料掺杂浓度的固体染料激光输出特性.研究结果表明掺杂浓度对输出激光波长影响明显,随着掺杂浓度的增加,激光输出波长红移,从激光增益出发,对该现象给出了理论解释.掺杂浓度对激光转化效率也有影响,当掺杂浓度为2×10^－4mol/L时,获得染料激光输出斜率效率最高达53.8%,抽运能量410mJ时,获得染料激光输出220mJ,激光带宽～8nm 关键词： 固体染料 宽带染料激光 PM580 聚甲基丙烯酸甲酯     

595 nm激光抽运双钨酸钇钠晶体激光特性研究

利用脉冲调Q染料激光对掺钕双钨酸钇钠晶体（Nd:NYW)的短波长吸收带（595nm)进行抽运，实现了1．064μm激光运转，在抽运能量24．2mJ时，获得的激光输出能量为1．08mJ,阈值抽运能量小于5mJ。     

Ce3+∶LiCaAlF6紫外激光器的研究

报道了利用Nd∶YAG四倍频266 nm脉冲激光端面泵浦Ce∶LiCAF晶体，采用平凹谐振腔，输出296 nm波长紫外激光.当输出镜透过率为20％，入射泵浦能量为13.5 mJ时，获得最大输出激光脉冲能量为270 μJ，脉冲宽度为3.4 ns，输出激光峰值功率为79.4 kW，光－光转换效率为2%，斜效率为1.6％.     

高强度泵浦碱金属蒸气激光器的光参量振荡器

以电光调Q的Nd:YAG激光器为泵浦源,以磷酸氧钛钾（KTP）为非线性晶体,搭建了调谐范围为750~800 nm的光参量振荡器。信号光在中心波长780.2 nm处获得单脉冲能量113 mJ、脉宽15.43 ns、光斑直径5.5 mm的输出。用光栅单色仪测量信号光光谱宽度（FWHM）为0.38 nm。信号光通过120 ℃的铷蒸气池,观察到清晰的荧光轨迹。证明信号光能有效泵浦铷蒸气,可为铷激光器提供峰值功率7 MW的高强度脉冲泵浦源,进而研究铷激光器在高强度泵浦条件下的动力学过程和基础物理机制。     

Injection-Seeded 500 Hz Repetition Rate High Peak Power Single-Frequency Nd:YAG Laser for Mid-Infrared Generation

We develop an injection-seeded single-frequency neodymium-doped yttrium aluminum garnet (Nd:YAG) laser with 500 Hz repetition rate and high peak power. The laser construction is designed as seed injection and master oscillator power amplifier (MOPA) including single-frequency master oscillator, extra-cavity frequency doubling crystal, and round-trip power amplifier. The master oscillator can emit 1,064 nm laser of 8.4 mJ with 6.8 ns pulse width at the pump energy equal to 23 mJ. A green laser energy of 1.1 mJ is obtained by setting the proper temperature of the LBO crystal. The pulse energy of 1,064 nm laser decreases to 6.5 mJ after passing through the LBO crystal and rises to 25.3 mJ after a round-trip power amplifier corresponding to the extraction efficiency of 29%. The final output pulse width is 6.5 ns, representing a peak power of 3.9 MW. The 1,064 nm laser beam quality factor M² of the master oscillator and the amplified one are 1.3 and 1.5, respectively. The laser will be used to generate mid-infrared where the 532 nm laser with narrow pulse width is to pump sheet optical parametric oscillator (OPO) and the 1,064 nm laser with high peak power to pump the OPO.     

基于脉冲CO2激光锡等离子体光刻光源的极紫外辐射光谱特性研究

研究了不同条件下脉冲放电CO₂激光烧蚀平板锡靶产生的等离子体极紫外辐射特性, 设计并建立了一套掠入射极紫外平焦场光栅光谱仪, 结合X射线CCD探测了光源在6.5～16.8 nm波段的时间积分辐射光谱,得到了极紫外光谱随激光脉宽, 入射脉冲能量及背景气压的变化规律。实验结果发现：入射激光脉冲能量在30～600 mJ变化时,极紫外辐射光谱的强度随辐照激光脉冲能量的增加而增加, 但并不是线性关系, 具有饱和效应, 且产生极紫外辐射的脉冲能量阈值约为30 mJ,当激光脉冲能量为425 mJ时具有最高的转换效率,此时中心波长13.5 nm处2%带宽内的转换效率约为1.2%。激光脉冲半高全宽在50～120 ns范围内变化时, 极紫外辐射光谱的峰值位置均位于13.5 nm,光谱形状几乎没有什么变化, 但是脉宽从120 ns变到52 ns后,由于激光功率密度的提高,极紫外辐射强度也随之增强了约1.6倍。极紫外光谱的强度随背景气压的增大而迅速下降, 当腔内空气气压为200 Pa时, 极紫外辐射光子几乎被全部吸收,而当缓冲氦气气压为7×104 Pa时,仍能够探测到微弱的极紫外辐射信号,计算表明100 Pa的空气对13.5 nm极紫外光的吸收系数为3.0 m-1,而100 Pa的He气的吸收系数为0.96 m-1。     

芴类荧光染料掺杂DNA-CTMA薄膜的放大自发辐射特性

钯催化Suzuki反应合成得到一种9,9-二乙基-2,7-二-(4-吡啶)芴（DPFP）荧光染料,研究了该染料的吸收和荧光光学特性,以及DPFP掺杂DNA-CTMA薄膜的荧光光谱特性和放大自发辐射特性。实验结果表明:DPFP的吸收峰位于333 nm,DPFP的荧光光谱在370 nm和386 nm出现荧光峰,在408 nm出现肩峰,存在从激发态S1能级到基态S0能级的S10-S00,S10-S01和S10-S02三种振动带的电子跃迁;同时,在Nd:YAG纳秒激光器355 nm输出光的泵浦下,DPFP掺杂DNA-CTMA薄膜在波长390 nm和406 nm处实现了放大自发辐射,其阈值能量密度分别为3.24和3.40 mJ/cm2;此外,通过调节DPFP掺杂DNA-CTMA的质量比可以实现特定波长的放大自发辐射。     

高峰值功率KDP晶体四倍频266nm紫外激光器

报道了一种灯泵浦结构的Nd:YAG晶体电光调Q高峰值功率266nm紫外激光器。结合磷酸二氢钾(KDP)晶体性质,基于倍频理论,分析了考虑走离效应情况下存在相位失配量时KDP晶体长度对转换效率的影响。该激光器采用紧凑的平平腔结构,灯泵浦Nd:YAG晶体电光调Q 1064nm激光作为基频光,腔外采用Ⅱ类匹配磷酸钛氧钾(KTP)和Ⅰ类匹配KDP分别作为二倍频和四倍频晶体。利用能量计、示波器等仪器进行测量,激光器重复频率1Hz时,获得脉宽6.0ns,单脉冲能量35mJ的266nm紫外激光输出,峰值功率高达5.83 MW;当重复频率10Hz时,获得单脉冲能量28.9mJ的266nm紫外激光。532~266nm转换效率最高可达31.9%。利用该高峰值功率、窄脉宽266nm紫外激光器,能够实现激光打标、激光雕刻。     

Amplified Spontaneous Emision of K2Yellow Band Excimer and Its Gain Measurement by e-beam-pumpingResearch on Injection-seeded β-BaB2O4Optical Parameteric Oscillator

The design of a high temperature cell appropriate for electron beam side pumping of alkali excimer lasers is described. By using the cell, an amplified spontaneous emission (ASE) and small signal gain coefficient of 4% cm-1 of the K2 yellow band (574 nm) were observed from the e beam excited mixture of K/K2 vapor with argon buffer gas. The dissociative recombination of K+3 is discussed as an efficient formation process of upper states by electron beam pumping.It has demonstrated the feasibility of a β-BaB2O4 optical parametric oscillator(OPO) without frequency control elements that produces very narrow bandwidth, 10 ns pulses via injection seeding. It was achieved by a CW He Ne laser and the experiment threshold for injection seeding is less than 1 mW. With 25 mJ pump energy at 354.7 nm, it has obtained pulse energy of 2 mJ at 632.8 nm and the total effiency is greater than 15%.     

宽带KrF激光泵浦SBS的研究

 理论和实验研究了宽带（15GHz）KrF激光泵浦的受激布里渊散射（SBS）在SF₆介质中的转换效率和脉宽压缩比的规律。介质在1.6MPa、透镜焦距为15cm和30cm时，测得SBS最大反射率分别为40%和45%，当泵浦能量大于60mJ时SBS反射率开始趋于平坦；介质在0.85MPa、透镜焦距在30cm时，SBS脉宽压缩比随泵浦能量的上升而下降，最大压缩比为5。建立了宽带多模KrF激光泵浦的SBS理论模型，假设宽带KrF激光光谱谱线由若干窄带谱线组成，这些窄带谱线之间在产生SBS过程中有一定程度的耦合。给出了理论模型结果，并与实验结果进行了比较。     

6.1 MW, 10 kHz Side-Pumped Burst-Mode Nd:YAG Laser

We present a compact high-peak-power, high-repetition-rate burst-mode laser from a master-oscillator power amplifier (MOPA) at 1064 nm for laser-based measurement applications. The oscillator is an 808 nm pulsed laser diode side-pumped acousto-optical (A-O) Q-switched Nd:YAG laser at repetition rates ranging from 10–100 kHz, producing a pulse train with a pulse number of 2–25. The maximum output energy of the oscillator is 15.6 mJ at 10 kHz, whereas it is 1.7 mJ at 100 kHz. After twostage amplifiers, a single-pulse energy of 85.2 mJ with a pulse-width of 14.5 ns is achieved at 10 kHz, which produces a peak power of 6.1 MW. At 100 kHz, the total burst energy reaches 220 mJ with a single-pulse energy of 8.8 mJ in the pulse burst laser system.     

Intracavity optical parametric oscillator pumped by passively Q-switched Nd:YLF laser

We report on a passively Q-switched end pumped Nd:YLF laser including a noncritically phase-matched KTP singly resonant intracavity optical parametric oscillator (IOPO-KTP). For the Q-switching operation we have used Cr:YAG saturable absorber. The optimized passively Q-switched Nd:YLF laser without IOPO generated linearly polarized pulses of 11.5 ns and 1.07 mJ at 1047 nm. The conversion efficiency of the optimized Q-switched pulse energy at 1047 nm to 1547 nm of a signal approached about 47%. For optimizing both Nd:YLF laser and IOPO we have numerically solved a theoretical model. We have achieved 1.6-ns duration pulses at 1547 nm with energy of 0.5 mJ and peak power of above 300 kW. The beam quality was excellent (M² ≈1).