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     

Stilbene 420激光染料的光谱特性分析

配制了Stilbene 420染料溶液。测量了其吸收光谱。以调Q倍频Nd∶YAG激光为抽运源,实现了对Stilbene 420染料的激光光谱和荧光光谱的分析。激光光谱在425 nm处获得最强峰值,半峰高宽(FWHM)为1 nm,光谱范围为420～440 nm。荧光光谱峰值在428.5 nm,与激光最强峰值相差3.5 nm。最高染料转换效率为9.26%。     

PBD系列紫外激光染料的光谱和激光特性

本文介绍一种具有宽调谐范围、高转换效率的PBD系列紫外波段激光染料的工作特性.在N_2激光泵浦下,其激光调谐区域为356～393nm;激光转换效率高于国外常用的同波段的BPBD激光染料.同时,还给出了PBD系列染料的吸收光谱、荧光光谱以及荧光量子产率等有关数据.     

国产掺铥双包层光纤光谱特性研究

对内包层截面为六边形的国产掺Tm3+双包层光纤的光谱特性进行了较全面的实验研究。在1064nm激光泵浦下,观察到掺铥光纤发出明亮的蓝光,对其上转换谱进行了测量,并分析了产生的机理。在785nmLD泵浦下,测量了光纤的荧光谱。选用3种不同透过率的输出镜,对长度分别为4.5m和2.2m的掺Tm3+光纤实现了2μm波段的激光输出;利用红外光谱仪测得了激光波长。实验获得最大输出功率达到5.1W,斜率效率41.9%,并对实验结果做了分析。     

甲醇和乙醇的三维荧光光谱特性研究

为阐明甲醇和乙醇的光谱学特性,建立两者快速的辨析方法。采用三维荧光光谱,对甲醇和乙醇的荧光特性进行了研究。分析结果显示,甲醇的三维荧光光谱中出现了两个特征荧光峰,其荧光强度在甲醇体积浓度小于15%时与其浓度成正相关,乙醇的三维荧光光谱中出现了一个完整的特征荧光峰,其荧光强度在乙醇体积分数小于50%时与乙醇浓度成相关,甲醇比乙醇具有更高的荧光效率,以甲醇为有机溶剂研究化合物的荧光特性时,需要考虑甲醇的本底荧光。甲醇和乙醇的特征荧光峰位置差别较大,前者特征荧光峰出现在225/35 0nm和250/375nm处,而后者特征荧光峰位于240/310nm,据此可以有效辨析两种醇。     

1 319和1 338 nm双波长Nd:YAG脉冲激光输出实验研究

 根据计算得到的双波长激光振荡的阈值条件,激光实验中对全反镜镀制1 319和1 338 nm的全反膜（其反射率大于99.73%,而对1 064 nm激光的反射率约为7%）;输出镜采用对1 064 nm强谱线95%的高透过率,而对1 319和1 338 nm谱线的透过率分别为34.7%,32.5%,有效抑制了强线1 064 nm振荡,成功实现了1 319和1 338 nm Nd:YAG同时双波长激光脉冲输出。当输入能量为125 J时,1 319和1 338 nm脉冲双波长激光的单脉冲总输出能量为0.89 J,电-光转换效率为0.71%,斜率效率为0.89%。输出的双波长激光的中心波长分别在1 318.8和1 338.2 nm处,谱线宽度（FWHM）分别为0.35和0.48 nm,强度之比为36:44。     

激光染料奇通红的光谱和激光性能

本文合成一种具有互变异构性能的新型激光染料奇通红.测试了该染料的光谱和激光性能.结果表明奇通红染料的吸收峰值在568nm,荧光峰值在593nm.阈值很低(～0.3mJ);能量转换效率大于40%.可以作为调谐激光染料系列红光区候选染料.     

基于离轴两反利特罗结构的棱镜高光谱成像系统的光学设计

为满足高光谱成像系统高空间分辨率和高光谱分辨率的要求,并应对实际应用中对仪器小型化、轻量化、高光学效率的新需求,研究一种基于利特罗结构的棱镜色散高光谱成像系统,采用离轴两反的利特罗结构形式减小光学系统的体积,同时为平面棱镜提供准直光路,并以宏编程的优化方式,避免系统中光路干涉。结果表明,通过非球面反射镜和双校正透镜的设计,该光学成像系统的谱线弯曲均小于2.1 μm,色畸变小于1.3 μm,控制在18%像元内,在400～1 080 nm可见—近红外(VNIR)工作波段的光学调制传递函数(MTF)均达到0.9以上,光谱分辨率为1.6～5.0 nm,光谱透过率在51.5%以上,系统在整个工作光谱范围都具有较高的透过率和像质。     

复合/单色光源检测红宝石吸收谱线的差异及分析

本文采用微型光纤光谱仪和复合光源联用的方式对红宝石样品进行了透过率光谱测试,并与紫外―可见光分光光度计测得的透过率光谱进行对比,发现红宝石透过率光谱在694nm主峰存在差异,并针对这一差异现象进行了荧光光谱实验。实验表明,复合光源中321nm～691nm波长的激发光可有效诱导红宝石产生以694nm为主峰的荧光,红宝石694nm处透过率光谱的形态由694nm光谱的发射与吸收程度共同决定。因此,采用复合光源的检测方式可得到与单色光检测方式不同的透过率光谱形态。本文对两种仪器的测量过程和其所用光源进行了对比分析,说明了光源能量分布对宝石光谱鉴定的影响,结果能够促进对宝石紫外可见吸收光谱鉴定的认识和改进。     

溶胶-凝胶法制备耐磨宽带SiO2/TiO2增透膜

以钛酸正丁酯[Ti(OBu)4]、正硅酸乙酯(TEOS)为原料，采用溶胶—凝胶(sol—gel)提拉方法在K9光学玻璃基片上镀制得高透过的λ／4～λ／2型宽带增透膜。该增透膜的表面均匀性良好，均方根粗糙度(RMS)为1.201，平均粗糙度(RA)为0．934，具有一定的耐擦除性。经200℃热处理，膜层中的OH吸收峰已基本消失，在400～700nm光谱范围的透过率比基片的平均透过率提高6．6％。为实现大面积涂覆“神光”装置主放大器的防爆隔板玻璃，大幅度提高主放大器的抽运效率奠定基础。     

Solid-state dye lasers based on polymethyl methacrylate doped with pyrromethene 650

Solid-state dye samples based on polymethyl methacrylate (PMMA) doped with different concentrations of the dye PM650 were prepared. With SHG of Q-switched Nd:YAG laser (532 nm, ∼15 ns) pumping the samples longitudinally, the fluorescence, lasing spectra and slope efficiencies of the samples were obtained. The highest slope efficiency 27.49% and laser output energy 22.0 mJ was achieved in the sample with a dye concentration of 2.0 × 10⁻⁴ mol/L. To our knowledge, the results are the best under the same condition so far. The maxima of output lasing spectrum is about 653.5 nm. Our results have shown that using solid-state samples doped with PM650 can extend the dye laser wavelength to the red.     

Enhanced laser characteristics of pyrromethene 650 using modified PMMA as solid hosts

Solid-state samples based on modified polymethyl methacrylate (MPMMA) with methanol doped with the dye pyrromethene 650 (PM650) are prepared.The effects of a volume percentage of methanol on the laser characteristics of the sample,including spectra properties,slope efficiency,photostability and tunable properties,are investigated.The broadband dye laser output wavelength is around 655 nm and a highest slope efficiency of 32.23% is achieved.Pumping the samples at a repetition rate of 5 Hz with a pulse energy of as high as 100 mJ (the fluence is 0.26 J/cm 2),the longest lifetime (168000 shots) is obtained in the sample (MMA:methanol=18:2),and the corresponding normalized photostability reaches 109.19 GJ/mol.When the sample (MMA:methanol=18:2) is placed in a Shoshan-type oscilla-tor,the narrow-linewidth operation is a continuous tuning range (up to 64 nm).The results indicate that the laser characteristics of solid-state dyes can be greatly enhanced by using modified PMMA with methanol serving as the solid host.     

PM567-Doped solid dye lasers based on PMMA

Polymers are a kind of attractive hosts for laser dyes due to their high transparency in both pumping and lasing ranges and superior optical homogeneity. In this paper solid dye samples based on polymethyl methacrylate (PMMA) doped with different concentrations of 1, 3, 5, 7, 8 -pentamethyl-2, 6-diethylpyrromethene-BF$_{2 }$ (PM567) are prepared. The absorption, fluorescence and lasing spectra of the samples are obtained. Wide absorption and fluorescence bands are obtained and a red shift of the maxima of the lasing emission spectra is observed. With the second-harmonic generation of Q-switched Nd:YAG laser (532\,nm, $\sim $20\,ns) pumping the samples longitudinally, the slope efficiencies of the samples are obtained. There is an optimal dye concentration for the highest slope efficiency when the pumping energy is lower than some typical value ($\sim $250\,mJ), and the highest slope efficiency 35.6{\%} is obtained in the sample with a dye concentration of $2\times10^{ - 4}$\,mol/L. Pumping the samples at a rate of 10Hz with a pulse energy as high as 200\,mJ (the fluence is 0.2\,J/cm$^{2})$, the output energy drops to one-half of its initial value after approximate 15500 pulses and the normalized photostability is 5.17\,GJ/mol. A kind of solid dye laser which could have some applications is built.     

Solid-state dye lasers based on PMMA co-doped with PM597 and PM650

In order to enhance the laser performances, solid-state samples based on polymethyl methacrylate (PMMA) co-doped with pyrromethene 597 (PM597) and pyrromethene 650 (PM650) were prepared. With SHG of Q-switched Nd:YAG laser (532 nm, ∼15 ns) pumping the samples, laser emission from the mixtures of PM597 and PM650 both in liquid solution and incorporated into solid polymeric matrices were investigated. The highest slope efficiency of co-doped solid-state dye samples 30.8% was achieved. Through the dye PM650 being co-doped into the dye PM597, the dye laser output wavelength was extended for the existence of energy transfer from the dye PM597 to the dye PM650.     

Highly efficient and photostable solid-state dye lasers doped with PM567 with the addition of Tinuvin770

Solid-state dye samples based on polymethyl methacrylate (PMMA) doped with pyrromethene 567 (PM567) with the addition of Tinuvin770 were prepared. The effects of a light stabilizer and concentration on the laser performances of the solid state dye PM567, including spectra properties, slope efficiency and photostability were investigated. The highest slope efficiency 66.6% was obtained in the sample (PM567:Tinuvin770 = 2.0:0.5). The addition of Tinuvin770 resulted in a dramatic enhancement of photo-stability. Pumping the samples at a rate of 5 Hz with a pulse energy as high as 100 mJ (the pump energy density was 0.26 J/cm²), the output energy dropped to half of its initial value after approximate 149500 shots and the normalized photostability reached 97.2 GJ/mol in the sample (PM567:Tinuvin770 = 2:5). All results have shown that a high efficient and photostable solid-state dye laser with the addition of Tinuvin770 can be obtained.     

Highly photostable solid-state dye lasers based on mixed pyrromethene 567 and coumarin 500

Solid-state dye samples based on polymethyl methacrylate (PMMA) co-doped with pyrromethene 567 (PM567) and coumarin 500 (C500) were prepared. The effects of C500 concentration on the performances of the solid state dye mediums, including spectra property, slope efficiency and photostability were studied. The highest slope efficiency 64.25% was obtained in the sample (PM567: C500 = 2: 8). Pumping the samples at a rate of 5Hz with a pulse energy as high as 100 mJ (the fluence was 0.26 J/cm²), the output energy dropped to half of its initial value after approximate 116130 pulses and the normalized photostability reached 75.48 GJ/mol in the sample (PM567: C500 = 2: 1). Our results have shown that it is possible to obtain a high-efficiency with a long-lifetime for a solid-state dye laser co-doped with PM567 and C500.     

Cr,Nd:YAG self-Q-switched laser with high efficiency output

The high efficient laser performance of self-Q-switched laser in the co-doped Cr⁴⁺,Nd³⁺:YAG microchip with 1.8 mm thickness was demonstrated. The slope efficiency is varied with the reflectivity of output coupler at 1064 nm, and the highest slope efficiency of 26% was obtained for 95% reflectivity of output coupler at 1064 nm. The pulse width, the single pulse energy and the pulse repetition rate for different reflectivity of the output couplers were measured, and the experimental results agree with the numerical calculations of the passively Q-switched rate equations. This can lead to develop the diode laser pumped monolithic self-Q-switched solid-state microchip lasers, especially for the intracavity frequency-doubled solid-state microchip lasers.     

Solid-state laser based on PMMA doped with Coumarin 540A

Solid-state dye laser materials based on polymethyl methacrylate (PMMA) doped with different concentrations of Coumarin 540A were prepared. The absorption, fluorescence and blue-green lasing spectra of the samples were obtained and studied in this latter. With the third harmonic generation (THG) of Q-switched Nd:YAG laser pumping the samples longitudinally, the highest slope efficiency is 12.8%, which is achieved in the sample with a dye concentration of 1.0×10^?3 mol/L.     

基于聚合物支撑形貌液晶/聚合物光栅的低阈值分布反馈式激光器

利用低光强曝光进行全息液晶/聚合物光栅(HPDLC)的制备,获得了内部无液晶微滴具有聚合物支撑形貌的低散射透射光栅结构.分别研究了染料PM567,DCM,DCJTI的放大的自发辐射(ASE)阈值及相对出射光强等性质,得到三种染料中DCJIT的ASE阈值最低,相对出射光强最高,表明DCJTI更适于制备低阈值、高转化效率激光器.分别采用这三种染料制备基于聚合物支撑形貌光栅的分布反馈式激光器,通过改变光栅周期得到不同出射波长的激光.其中,以DCJTI为工作物质,得到中心波长为648 nm,阈值为0.65μJ/pulse,转化效率为1.6%,线宽为0.3 nm的高性能激光.与国内外同类激光器相比,在阈值、转化效率、线宽三个方面均有不同程度的提高.