利用HCD灯测量Gu亚稳态寿命

铜原子能级中存在着两个亚稳态能级(4d~94s~(22)D_(3/2)和4d~94s~(22)D_(5/2)。它们分别是铜蒸气激光器578.2nm和510.6nm激光跃迁的下能级。过去已经在CuCl正柱放电管中测量过这二个亚稳态能级的寿命,在不同的条件下,得到的结果也不尽相同,大致在10到100μs的范围内。利用HCD灯,我们发展了一种新的利用窄脉冲放电激发HCD灯产生Cu亚稳态粒子并在放电结束后测量共振激光感生荧光强度随激光脉冲对放电脉冲延迟时间的衰减关系来测量亚稳态寿命的方法。这里的激光波长共振于下能级为亚稳态的跃迁,即510.6nm:     

CO_2分子激光跃迁谱带受激发射截面的测量与研究

论文报导了CO_2分子激光跃迁谱带受激发射截面σ(γ)的最新研究结果。σ(γ)是分析和计算CO_2分子激光振一转能级粒子数反转过程所必需知道的确切量。σ(v)值已知时,即可计算出谱线中心增益g_0,粒子数反转密度△n,以及谱线加△γ、受激发射系数B_(21)、振子力f等跃迁强度参量、 据由速率方程导出的σ(v)测量式,用脉冲增益放大技术测量了不同工作条件下CO_2分子常规跃迁谱带的受激发射截面,获得近100个σ(γ)的确节测量值。同时,论文根据σ(v)的定义,导出σ(v)的理论计算式,并计算了相应的σ(v)理论值。实验值与理论值进行比较,表明有良好的一致性。最后分析了σ(v)值与转动量子数J、气压P、温度T以及混合     

铷原子4D_(5/2)态双光子偏振光谱及其在1.5μm激光稳频中的应用

介绍了基于87 Rb原子5S1/2-5P3/2-4D5/2阶梯型能级系统中的双光子偏振光谱。与其他跃迁相比,循环跃迁的信噪比最好。研究了双光子偏振光谱循环跃迁线信号强度随抽运光光强的变化情况。利用双光子偏振光谱,将1529nm半导体激光器的频率锁定于87 Rb原子的5P3/2(F′=3)-4D5/2(F″=4)跃迁线上,当取样时间τ=100s时阿仑方差最小,为σy(τ)=1.3×10-11。与自由运转相比,该方法显著地改善了1529nm激光器长期频率稳定度。     

铜蒸气激光器实现32瓦运转

铜蒸气激光器是一种自终止跃迁的高增益气体放电激光器,它能实现高功率、高效率运转.它的发射为可见光谱绿线(510.6nm)和黄线(578.2nm).我所自从1983年开展铜蒸气激光器的研究工作以来,先后在(?)23×1000mm的放电器件上.用6～10kHz的脉冲重复频率实现了10W、15W、23W的运转;工作寿命超过200小时.去年,我们在(?)35×     

1319nm和1338nm单谱线Nd:YAG连续激光器

YAG晶体中,Nd3+离子4F32-4I13m次跃迁产生1319m和1338nm激光,此两谱线跃迁截面接近,约为4F3z-4I11/2主跃迁截面的1/5,为了高效地获得所需次跃迁的单谱线激光,采用三色镜技术抑制了主跃迁和另一不要的次跃迁谱线.研制成以下次跃迁的单谱线激光:1)激光二极管(LD)抽运1319 nm或1338 nm TEM00模Nd:YAG连续激光器.输出功率为200 mW,光光转换效率为20%;2)氪灯抽运1319 nm TEM∞Nd:YAG连续激光器.输出功率为6 W,电光转换效率为0.12%;3)氪灯抽运高功率1319nm Nd:YAG多模连续激光器.输出功率为100 W,电光转换效率为1.67%;     

金属蒸气激光的特性

(1)测量了CuBr激光(510.6nm,578.2nm),锰激光(534.1nm)和金激光(627.8nm)谱线的线型与放电管温度、缓冲气体氖压强和电压的关系。并与计算得到的原子自发辐射线型作了比较。发现这些激光谱线的单色性在较高的缓冲气体压强下有了改善。线型的时间演变提供了激光脉冲的立体图象。线型的几个峰出现的次序由各自谱线的超精细分量的     

确定激光材料光谱参数的简单方法

在探索和研究激光材料的工作中,常常需要系统地大批地测定材料的光谱参数,例如荧光寿命τ、受激发射截面σ(或增益系数β)和量子效率η)等。这些量的绝对测量虽然已比较成熟,但对于大量的、系统性的激光材料测量,尚存在许多不便。这里介绍一种简单的方法。 对于任意线型的荧光带(或线)的辐射跃迁几率A为: A=8πn~2c·Δλ·σ_P/λ~4 (1) 其中σ_P为峰值受激发射截面,λ为荧光带的平均波长,Δλ是荧光有效带宽,c为光速,n为介质的折射率。积分荧光强度I_p与荧光跃迁初始能级的粒子数密度和相应的跃迁几率成正比 I_p=8πn~2c~2h·σ_p·N/λ~5 (2)其中N是荧光初始能级的粒子数密度。如果采用稳定的弱激发,在稳态条件下 N=N_0σ_AI_Eτ (3)式中No为样品中的总粒子数密度(或基态粒子数密度),σ_A为光泵吸收截面,I_E为平均激发光强,对于固定的实验条件I_E可认为是不变的,τ是荧光能级的寿命。     

准分子Xe_2Cl的增益观测

引论众所周知,三原子稀有气体卤化物准分子激光是由电子跃迁产生的。它的光学跃迁属于“束缚-自由”型跃迁,从束缚的离子激发态跃迁到排斥的基态。由于它们的激光跃迁下能级(例如Xe_2Cl的X(1/2),A(3/2),A(1/2)态)和双原子稀有气体卤化物的A态(例如XeCl的A~2∏_(1/2,3/2)态)相类似,有着陡峭变化的结构,所以这种准分子具有宽带发射特性。其带宽的典型值是50nm到120nm。它们在230nm(Ar_2Cl)到670nm(Xe_2F)的宽阔频谱范围内存在着制成可调谐准分子激光器的潜在可能     

LBO I类临界相位匹配腔内和频572 nm黄光激光器

首次报道了全固态连续波572 nm黄光激光器,黄激光是分别由两片Nd: YAG的1444 nm和946 nm谱线非线性和频产生,两条谱线在各自晶体对应能级跃迁分别为~4F_(3/2)-~4I_(15/2)和~4F_(3/2)-~4I_(9/2).实验中采用复合腔结构,利用LBO晶体I类临界相位进行内腔和频,当注入到两片Nd: YAG晶体的泵浦功率分别为24 W和14.8 W时,获得592 mW的TEM_(00)连续波572 nm黄激光输出.4 h功率稳定度优于±3.6%.     

实现Na_2~3∑_g~+-x~3∑_u~+强辐射的新途径

本文报道了用共振泵浦Na 3P态,通过Na(3P)+Na(3S)而获得Na_2b~3∑_g~+态粒子数布居 的可能,在100mbar缓冲气压下,T=500℃,用589.0nm泵浦得到位于第一三重态跃迁范围内的荧光谱。当泵浦波长偏离共振线时,得到的荧光谱迅速消失,说明该谱区确是由共振3P泵浦而产生的。     

铜激光光脉冲的时间特性

测量了铜激光两种波长510.6nm和578.2nm光脉冲的抽运时间与氖压和充电电压间的关系。波长578.2nm的光脉冲的抽运时间在不同氖压下随电压的增加而缩短。波长510.6nm光脉冲的抽运时间与电压的关系对氖压较为敏感。     

Optimization of a UV Cu+ laser excited bypulse-longitudinal Ne-CuBr discharge

The discharge conditions for high average output power on four UV Cu⁺ lines at 248.6 252.9, 260.0, and 270.3 nm, in a nanosecond pulse-longitudinal Ne-CuBr discharge, have been investigated in two discharge tubes of different designs. A record average output power of 210 mW (and a peak pulse power of 1.7 W) on the 238.6-nm laser line, and of 270 mW for multiline operation has been obtained. An optical effect enhancing the 248.6-nm laser line power has been observed as the intensity of two Cu atom laser lines (510.6 and 578.2 nm) increases. It has been shown that the presence of Br atoms in the discharge leads to a fall of the Ne metastable density via Penning ionization and, hence, to a decrease of the Cu⁺ metastable density and an increase of the laser output     

Mechanisms of the increase of the Cd(II) 441.6 nm laser power by the addition of iodine in a positive column He-Cd+laser

The population densities of the He(I)2^{3}Sand2^{3}Plevels and the Cd(II) ground level were experimentally determined with the modified absorption method in a positive column He-Cd laser discharge with little iodine. The population densities of the upper and lower laser levels of the Cd(II) 441.6 nm line were also obtained with the modified absorption method and the gain measurement. From these results, the mechanism of the increase in the Cd(II) 441.6 nm laser power with the addition of iodine was made clear.     

铜蒸气激光器

以纯铜或铜的卤化物蒸气作激光工作物质,利用高重复频率谐振布鲁林放电线路激励,得到5106(?)和5782(?)激光输出.当充电电容量为1.5毫微法,充电电压6000伏,脉冲重复频率16千赫时,激光平均输出功率为1.2瓦.     

Gain measurements on one, two, and three strained GaInP quantumwell laser diodes

We report on systematic investigations of the modal gain below threshold for one, two, and three compressively strained 680 nm AlGaInP quantum well lasers using the Hakki-Paoli method. Accurate values of the gain are obtained by carefully spacial filtering the light for the fundamental waveguide mode. Gain flattening and peak gain shifts are observed even at moderate pumping levels. It is shown that the gain scales very well with the number of quantum wells. We also observe that gain flattening starts at current densities per quantum well of 700 A/cm ²     

铜蒸气激光振荡器与放大器中的黄绿光脉冲及其对R6G染料激光输出效率的影响

本文从实验上研究了铜蒸气激光振荡器从振荡到稳定输出过程中黄光脉冲(578.2nm)与绿光脉冲(510.6nm)的强度变化、振荡放大系统中触发延时对放大器两种激光脉冲的强度和相对延迟的作用,并指出R6G染料激光的输出效率不但与泵浦光—铜蒸气激光的黄绿光强度比的大小有关,并且还与这两种光脉冲的相对延迟的大小有明显关系.     

A copper HyBrID laser with 2 W/cm3 specific averageoutput power

A copper HyBrID laser (λ510.6, 578.2 nm) is reported, which produced an average output power of 9.5 W from an active volume of just 4.77 cm³. These figures correspond to a record specific average output power for copper lasers of any type of 2.0 W/cm³      

Fluorescence and superfluorescence line narrowing and tunability ofNd3+ doped fibers

The inhomogeneous behavior of the 1.06 μm-neodymium transitions in doped optical fibers have been investigated, using the fluorescence line narrowing technique, pumping on the ⁴F_3/2 and ⁴F_5/2 sublevels at 4 K. Each observed transition has been identified. As the pump wavelength varies, the shift of the main fluorescence line is 40 nm, with the two pumping levels. We have studied the spectral behavior of the superfluorescence as a function of the pump wavelength, the temperature, and the absorbed power. The spectral evolution depends on λ_p with 19 nm-tuning range at low temperature. At 300 K, the quasihomogeneous behavior of the transition decreases the tunability to 14 nm. Based on these results, we present a simple technique permitting precise prediction of gain and spectral line shapes of superfluorescent Nd-doped fiber sources     

射频磁控溅射ZnO薄膜的光致发光

用射频磁控溅射法在硅衬底上沉积出具有良好的择优取向的多晶ZnO薄膜.在室温下进行光致发光测量,观察到明显的紫光发射(波长为402nm)和弱的紫外光发射 (波长为384nm).紫光发射源于氧空位浅施主能级到价带顶的电子跃迁;紫外光发射则源于导带与价带之间的电子跃迁.随着光激发强度的增加,紫光发射强度超线性增强,且稍有蓝移,而紫外光发光强度则近似线性增加.在氧气中高温退火后,薄膜结晶质量明显提高,紫光发射强度变弱,紫外光发射相对增强.