掺杂PM597的聚合物固体染料激光特性研究

固态染料激光器结构紧凑、应用简便、无污染、成本低,是目前染料激光器的一个发展方向.PM597是一种高效的激光染料,实验制备了掺杂不同浓度的PM597的聚合物基质的固体染料,并对其荧光光谱、激光光谱和斜率效率进行研究.固体染料具有宽带的荧光特性,荧光谱的带宽约为60 nm;激光光谱半宽约为10 nm,激光光谱的峰值波长随染料浓度的增加而发生相应的红移;PM597的浓度存在一个最佳值(2×10-4 mol/L),使介质的斜率效率达到最高,斜率效率高达50.9%.     

染料掺杂手性向列相液晶激光器的制备和研究

设计制作了PM597染料掺杂手性向列相液晶器件,研究了其激光辐射行为。混合激光染料PM597、手性剂S-811、向列相液晶TEB30A,制成平面态织构的手性向列相液晶激光器件。采用固体Nd∶YAG倍频532nm波长激光作为抽运光,在光子禁带短波和长波边沿同时获得波长分别为571.1、615.5nm的激光输出。对于器件产生激光辐射的机理,采用光子态密度理论进行了分析,根据实际样品各成分的配比,模拟出态密度随波长的变化曲线。在器件中,光子禁带边沿处光子态密度最大,此处器件阈值较低,容易产生激光辐射。     

固体染料激光器的研究进展

综述固体染料激光器的发展及研究最新成果。系统地阐述了固体染料激光器的基质、抽运光源、染料光稳定性和新型激光染料合成等方面。     

可调谐激光器的固体化趋势

本文综合性地评述了由于掺钛蓝宝石等固体可调谐激光器的问世,在可调谐激光技术领域出现的由液体(染料)可调谐激光器向固体(过渡金属离子,光参量振荡)可调谐激光器转变的发展趋势,以及全固化的发展方向。     

染料掺杂手性向列相液晶器件中实现随机激光辐射

设计制作了染料掺杂手性向列相液晶器件,研究了其随机激光辐射行为。均匀混合激光染料DCM和PM597、手性剂S-811、向列相液晶TEB30A,注入无摩擦取向的40μm液晶盒,制成焦锥织构态的手性向列相液晶激光器件。采用固体Nd:YAG倍频532nm波长的脉冲激光作为抽运光泵浦样品。掺杂激光染料PM597和DCM的液晶器件分别在575～588nm和600～620nm范围显示了尖锐、分立的随机激光辐射峰,线宽约为0.3nm。探测了器件在不同方向上的激光辐射谱,在与样品表面夹角约为45°～150°的范围内均能探测到随机激光。在器件中,手性向列相液晶焦锥织构态对光的强散射作用是随机激光产生的主要原因。     

专利与文献

本书共两部分:(1) 非稳腔、波导共振腔、环形激光共振腔和具有反射率可变反射镜的共振腔的基本原理,激光频率的稳定和多模激光束传输;(2) YAG激光器、染料激光器、高功率激光器、激光二极管泵浦固体激光器、光纤激光器、CO_2波导激光器和准分子激光器用的共振腔的工艺。     

基于电光调Q1064nm/532nm/570nm三波长固体激光器

为了提升激光技术在色素性疾病治疗等生物医学应用效果, 研制了一种1064nm, 532nm, 570nm三波长激光器。采用电光调Q Nd:YAG激光器获得最窄脉宽为11ns的1064nm脉冲激光输出, 使用磷酸氧钛钾(KTP)非线性晶体对基频光腔外倍频获得532nm激光输出; 以固体染料块为激光增益介质, 倍频光为抽运光, 可获得中心波长为570nm的黄光输出, 光光转换效率为61.3%。结果表明, 通过改变氙灯注入电压, 可以调节1064nm激光脉冲输出特性; 增加固体染料激光器腔长, 可以调节染料激光输出光谱特性。该研究结果对激光器灵活应用具有重要意义。     

若丹明6G掺合在P（MMA＋MAA）共聚物中的固体染料激光研究

用共聚合方法制备了若丹明６Ｇ掺合在Ｐ（ＭＭＡ＋ＭＡＡ）共聚物中的固体染料样品,对其进行了光谱和激光性能的研究,得到了泵浦光－染料激光转换效率１５％,激射寿命２万脉冲以上的固体染料激光输出,并和其它基体的若丹明６Ｇ固体染料激光进行了比较,对激光染料光和热稳定性进行了讨论。     

固体激光器的新进展

大约五年前,美国海军研究内务助理秘书Theodore Jacobe博士在San Diego发表的一次讲话中,将激光器分为三个主要的研究领域,即“气体”、“染料”和“玻璃”激光器,而通常认为玻璃激光器属于固体激光器。当时,化了很大的努力,进行高功率气体激光器的军事应用的研究工作和探索气体激光装置用于核聚变驱动器的可能性。那时,固体激光器研制工作确实相当活跃,但按照Jacobe的观点,气体激光器似乎最有发展前途。本文不评述“气体”和“染料”激光器的发展前景,只介绍固体激光器的某些新进展。为了简短起见,当然也不介绍半导体激光器、色心激光器这些固体激光器。     

可调谐固体激光材料

可调谐固体激光材料传统习惯是，需要可调谐性的场合都使用染料激光器，但由于它们存在诸多缺点，如使用技术苛刻，相应安全性问题，为运转和维持高性能染料激光系统需有较高水平的专门技能等，已日益为固体激光器所代替。尽管闪光灯泵浦的可调谐紫翠宝石系统加速了固体激...     

共聚物基质固体染料激光介质的特性

聚合物基质光学均匀性好、对抽运光和染料激光透过率高、与染料分子相容性好、制备简单、成本低。制备了吡咯甲川567(1, 3, 5, 7, 8-pentamethyl-2, 6-diethylpyrromethene-BF2,PM567)掺杂的以甲基丙烯酸甲酯(methyl methacrylate, MMA)和甲基丙烯酸-β-羟乙酯(2-hydroxyethyl methacrylate, HEMA)的共聚物为基质的固体染料激光介质,研究了(HEMAMMA)对介质特性的影响。利用10 Hz重频调Q的Nd:YAG的倍频光纵向抽运固体染料激光介质,研究了介质的输出特性。介质的抽运阈值小于10 mJ/cm2,HEMA含量存在一个使得介质的斜率效率达到最高的最佳值。在HEMA体积分数为25%的介质中得到最高的斜率效率56.2%。以10 Hz重频,脉冲能量17.5 mJ(能量密度为0.02 J/cm2)调Q的Nd:YAG的倍频光纵向抽运固体染料介质,V(HEMA)V(MMA)=1:1的介质经约123000个抽运光脉冲后,输出下降为初始输出的一半,归一化的光稳定性为10.8 GJ/mol。     

879 nm激光二极管抽运准三能级Nd:GdVO4激光器

利用879 nm新型激光二极管(LD)抽运Nd:GdVO4晶体,在室温下实现了4F3/2→4I9/2准三能级激光谱线跃迁。对掺杂原子数分数0.2%,3 mm×3 mm×3.8 mm的晶棒,在抽运功率为33 W时,获得912 nm最大输出2.5 W,斜率效率11%,相应的对吸收抽运功率的斜率效率达38%;对掺杂原子数分数0.2%,3 mm×3 mm×5 mm的晶棒,在抽运功率为33 W时,获得912 nm最大输出功率3.0 W,斜率效率16%,相应的对吸收抽运功率的斜率效率达45%。在腔内插入声光(AO)Q开关,当重复频率为10 kHz时, 获得了脉冲宽度为22 ns,平均功率为660 mW,峰值功率达3 kW。理论上分析了晶体的长度、浓度与准三能级激光器振荡阈值的关系,讨论了再吸收损耗对激光器的运转状态产生的影响,并通过实验观察了再吸收损耗的饱和效应。     

运用波长与光纤长度关系选择激光波长

推导了掺Yb 光纤激光器中激射波长与掺杂光纤长度、掺杂浓度等的关系式。依据所得到的关系式,在981.5 nm 半导体激光抽运的掺Yb 环形腔石英光纤激光器中,获得了中心波长在1053nm 的激光输出。光抽运阈值功率为1.85 m W。激光半功率宽度(FWHM)为5 nm ,输出功率为104μW,斜率效率为3% 。激光空间模式为基横模。     

室温下运转的LiF：F_2~＋色心可调谐激光器

本文给出了室温下运转的ＬｉＦ：Ｆ２＋色心可调谐激光器的实验结果和激活色心的动态分析，采用Ｎｄ：ＹＡＧ倍频５３２ｕｍ脉冲激光作为泵浦源，用闪耀光栅作调谐元件，得到波长范围为８５０～１０５０ｕｍ，峰值在９３０ｕｍ的脉冲可调谐激光，斜率效率为１．５％。     

Phase-conjugation property of one-photon pumped backward stimulatedemission from a lasing medium

Optical phase-conjugation properties of the backward stimulated radiation from a one-photon pumped lasing medium have been studied. The gain medium is a dye solution (pyrromethene 597 in ethanol) or the same dye doped poly(methyl methacrylate) (PMMA) rod pumped with ~7-ns and 532-nm laser pulses. A highly directional and phase-conjugate backward stimulated emission at ~573 nm wavelength could be obtained with a conversion efficiency of ~42% by using a 1-cm-long dye solution sample at the concentration level of d₀=0.000 15 mol/L. The spectral, temporal, output/input, and phase-conjugation properties of this backward stimulated emission are presented in detail. The induced aberration influence, which is much larger than the divergence angle of the input pump beam, can be basically removed by the backward stimulated emission; however, the fidelity of the near-field detail for the backward stimulated emission is relatively poor. A quasi-collinear holographic interaction model and a mathematical analysis are presented to explain the basic experimental results     

Ytterbium-doped glass waveguide laser fabricated by ion exchange

A ytterbium-doped, glass, channel waveguide laser, fabricated by ion exchange, is reported. The 2.2 cm long device, using broad-band 4% output couplers, lased in the vicinity from 1020 to 1030 nm when pumped by a Ti:sapphire laser operating at 910 nm. A lasing threshold of 50 mW (launched pump) and a slope efficiency of 5% were measured. Device parameters, including fluorescence lifetimes, emission and absorption cross sections, propagation losses, and mode profiles were experimentally determined and laser performance was analytically modeled using this data     

Lasing properties of chromium-aluminum-doped forsterite pumped withan alexandrite laser

The lasing properties of chromium-aluminum-doped forsterite were investigated using a tunable alexandrite laser as the pump source. Results of measurements of the lasing threshold, slope efficiency, spectral and temporal profiles of the laser pulse, and the time delay between the alexandrite pump pulse and the laser emission are presented for pump wavelengths of 770, 746, and 730 nm and different pump beam energies. Laser rate equations are developed to model the lasing center as a four-level system and applied to the case of 746-nm pumping     

Laser-diode pumping of waveguide laser based on Nd-doped silica planar lightwave circuit

The authors describes an improvement in the lasing threshold in Nd-doped silica planar-lightwave-circuit (PLC)-type lasers fabricated on Si substrates in which the scattering loss was reduced by an improved fabrication technique. Lasers with core widths from 6 to 30 mu m were fabricated by flame hydrolysis deposition and reactive ion etching techniques. Based on an investigation of the lasing threshold dependence on core width, a minimum lasing threshold was obtained in a waveguide laser with an 8 mu m wide core. A threshold of 25 mW and a slope efficiency of 1.2% for laser-diode pumping at 805 nm were obtained in the waveguide laser.<>     

Characterization of radiative and nonradiative Processes in Nd:YAG lasers by comparing direct and band pumping

Heat generation and laser performance of Nd:YAG oscillators pumped in two regimes, band pumping at /spl sim/808 nm and "thermally boosted" (TB) pumping at 884.5 nm, are compared. The crystal, pumped with a Ti:sapphire laser, lased with slope efficiencies of 52% and 57% when pumped at 802 and 884.5 nm, respectively. The heat generated during lasing was found to be 27% lower with TB pumping as compared to traditional band pumping. Moreover, the experimental results suggest that the coupling efficiency between the pump band and the upper lasing level (the quantum efficiency) is unity, and about 8% of the upper lasing level population decays via nonradiative channels.