高气压TE CO_2激光泵浦的高功率连续可调谐远红外喇曼NH_3激光器

本文报道输出能量约4mJ(功率约80 kW)的连续可调谐远红外喇曼跃迁NH_3激光器,调谐范围约覆盖发射谱从90到93μm的70％。分立K能级激光跃迁的连续调谐范围约为30GHz。文中给出了典型的实验结果,并进行了讨论。     

13CH4分子v3振动带空气和氮气加宽系数温度依赖性研究

采用中红外波段连续可调谐二极管激光器和自行研制的低温吸收池, 测量了温度为296 K, 252 K, 213 K, 173 K时, 3.38 μm附近¹³CH₄分子的四条跃迁谱线的氮气和空气加宽光谱; 首次通过实验获得空气和氮气对¹³CH₄分子的碰撞加宽系数, 以及谱线加宽系数的温度依赖系数. 实验过程中, 利用Voigt线型对所测量的光谱进行拟合. 实验结果表明, 氮气和空气对¹³CH₄分子的碰撞诱导加宽系数随温度的降低而增大; 相同温度下, 氮气对¹³CH₄分子的碰撞加宽系数普遍大于空气加宽系数. 实验数据为地球和外星体大气遥感探测提供了依据.     

调谐激光晶体Cr3+:ZnWO4光致发光特性的研究

研究了调谐激光晶体Ｃｒ³⁺：ＺｎＷＯ₄的光致发光特性。报道了它的吸收光谱、激发光谱、发射光谱及其随温度的变化、零声子跃迁和发射寿命等实验结果，并讨论了激发特性、电子－声子耦合作用、ＺｎＷＯ₄中Ｃｒ³⁺的发射寿命曲线等相关问题。 关键词：     

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：     

镱原子超精细诱导5d6s 3D1,3→6s2 1S0 E2跃迁及超精细常数的精确计算

在镱原子中,利用5d6s³D₁→6s²¹S₀跃迁探索宇称破缺效应已经得到了深入的研究.但是5d6s³D₁态与基态6s²¹S₀之间的M1跃迁和超精细诱导E2跃迁很大程度上影响了宇称破缺信号的探测.因此,很有必要精确计算5d6s³D₁态与基态6s²¹S₀之间的M1跃迁和超精细诱导E2跃迁的跃迁概率.本文利用多组态Dirac-Hartree-Fock理论精确计算了5d6s³D₁→6s²¹S₀ M1跃迁和超精细诱导5d6s³D_1,3→6s²¹S₀ E2跃...     

K5Bi0.9Er0.1(MoO4)4的晶体生长和光学性质

在化学计量的熔料里,用提拉法生长了K₅Bi_0.9Er_0.1(MoO₄)₄单晶。该晶体属于三方晶系,空间群为R3m,z=1.5,晶胞参数为a=6.029?,c=20.823?(六方表示)。晶体具有层状结构,沿着(0001)面容易解理。晶体在室温下的吸收光谱包括有若干条吸收带,它们是稀土离子所特有的。其中三个主要的吸收峰分别相当于从Er³⁺离子的基态 ⁴I_15/2向 ⁴G_11/2, ²H_11/2和 ⁴I_13/2能级的跃迁。本文还给出晶体中相当于 ⁴I_13/2→ ⁴I_15/2跃迁的荧光发射光谱。 关键词：     

真空紫外光激发下Ce3+、Tb3+激活的BaCa2(BO3)2的发光性质

利用XRD、VUV及UV光谱等方法对Ce³⁺、Tb³⁺离子掺杂以及Ce³⁺、Tb³⁺离子共掺的3种BaCa₂(BO₃)₂荧光粉的相纯度、发光性质、浓度猝灭现象进行研究。结果表明:3种荧光粉在VUV波段有较好的吸收,基质吸收带位于140～190 nm范围。Ce³⁺在BaCa₂(BO₃)₂的最低4f5d跃迁带位置在360 nm附近,其5d→²F_J(J=5/2, 7/2)发射峰分别位于393,424 nm。Tb³⁺掺杂的样品在172 nm激发下的发射光谱由4个窄带组成,分别对应⁵D₄→⁷F_J(J=3,4,5,6)的跃迁,其中占主导位置的是⁵D₄→⁷F₅的跃迁,大约位于543 nm处,主要为绿光发射。在Ce³⁺,Tb³⁺离子共掺杂的BaCa₂(BO₃)₂光谱中,观察到Ce³⁺-Tb³⁺离子间有能量传递。     

高离化类铍离子2s21S0—2s2p3P1(Z=10—103)自旋禁戒光谱跃迁

利用全相对论性多组态Dirac-Fock平均能级(MCDF-AL)方法系统地计算了高离化类铍离子自 旋禁戒2s^{2 1}S₀—2s2p³P₁(Z= 10—103)跃迁的能级间隔和跃迁概率,计算中考虑了重要的核的有限体积效应,Breit修正 和QED修正,所得结果和最近的实验数据及理论计算值进行了比较,结果表明：高原子序数 的高荷电离子的自旋禁戒跃迁的跃迁概率和中性原子的电偶极E1的相当,在ICF和MC 关键词： 高离化态 跃迁概率     

In0.15Ga0.85As—GaAs应力层多量子阱中束缚子带—连续带跃迁

在10—300K温度范围,研究了稳态发光二极管(LED)辐照对15周期的In_0.15Ga_0.85As(8nm)-CaAs(15nm)应力层多量子阱的光电流谱的影响。各跃迁过程对应的光电流峰的强度随LED光强的增大而减弱,并且具有不同的变化规律。据此可区分出束缚子带和连续带间的跃迁及其亚结构,并由跃迁的能量位置,直接确定导带和价带的不连续量,得出重空穴价带的能带台阶Q_v=0.38±0.01。 关键词：     

类钾离子4s 2S1/2─3d 2D3/2电四极矩E2光谱跃迁的理论研究

采用全相对论量子力学GRASP²程序,广义平均能级EAL模型,在核的有限体积效应,Breit和QED效应的高阶扰动基础上,考虑到原子实的极化,系统地计算了高剥离类钾离子4s ²S_1/2─3d ²D_3/2电四极矩E2光谱跃迁的能级间隔,跃迁概率和振子强度,结果表明：考虑原子实极化效应后,计算的精细能级结构间隔与实验数据之间的系统误差基本消除,其跃迁概率和振子强度属首次报道. 关键词： 高剥离态 能级间隔 振子强度     

A simple microcomputer- controlled CO2 laser wavelength tuning system

A CO₂ laser wavelength tuning system with microcomputer-controlled diffraction grating positioning is reported. The system employs a dc micromotor operating in a closed loop positioning servo and is characterized by simplicity of hardware. Fast wavelength tuning over a broad spectral range is achieved with the variable positioning speed technique. System performance is evaluated in conjunction with a TEA CO₂ laser.     

A tunable waveguide CO2 laser using Fabry-Perot modulator and fox-smith type mode selector

A tunable waveguide CO₂ laser was constructed and tested. Efficient output was obtained over expanded tuning range making use of the coupling modulation through the F-P modulator. A fox-smith type mode selector was used to obtain the tuning range wider than the longitudinal mode spacing.A continuous tuning range of 2.2GHz was experimentally obtained.     

高Tc氧化物YBa2Cu3Oy超导体中的磁通蠕动

利用观察磁化随时间变化的方法研究了高T_c氧化物YBa₂Cu₃O_y超导体临界态的磁通蠕动。实验结果表明,零场冷却的样品,加一个所选定场值的磁场,产生的磁化随对数时间线性衰减,同时伴随有磁通跳跃的发生。磁化衰减速率dM/dlnt随外场H的变化在H=3H_P附近有一峰值,并认为与弱连结超导电性的存在有关。在77K以上温度,dM/dlnt随温度的升高而单调减小。讨论了钉扎磁通的热激活能U_{0关键词：}     

Continuous tuning characteristics of a small high pressure uv preionised CO2 laser

The wavelength tuning characteristics of a compact uv preionised CO₂ laser operating at pressures in the range 8–12 atmospheres are reported. This laser, with a gain length of 16 cm, is demonstrated to have a continuous tuning range of 17 cm^-1 in the 10.4 μm P-branch and 12 cm^-1 in the R branch at 10 atmospheres.     

A tunable waveguide CO2 laser with expanded tuning range

A method of expanding the tuning range of the CW CO₂ waveguide laser making use of a Fabry-Perot type light modulator is proposed. A preliminary experiment has been done to confirm the workability of the proposed scheme.     

强脉冲CO2激光与靶材在空气中的相互作用

用高速干涉摄影诊断手段对激光作用在固体靶材上的表面效应,冲击波的传播、反射及绕射机制进行了实验观察,拍摄了各种现象的干涉及阴影照片,并进行了简要的分析。 关键词：     

Theoretical study on gain and tuning characteristics of infrared-microwave pumped NH3 FIR laser

Based on the semi-classical density matrix equation theory, the gain and tuning characteristics of infrared-microwave pumped NH₃ FIR laser were studied. It was shown that quasi-continuously tuning could be obtained by the tuning of microwave frequency and the efficiency of the laser could be enhanced by electric dipole transition enhancement effect, but compromise should be made between FIR laser output and frequency tuning range.     

High precision spectroscopy of SF6 with cw high pressure tunable CO2 laser

Investigations are reported on the frequency characteristics of the cw high pressure CO₂ laser and its use for high precision spectroscopy. The problem of using a cw tunable CO₂ laser with a mixture of a few isotopes (¹²C¹⁶O₂, ¹²C¹⁸O₂, ¹²C¹⁶O¹⁸O and others) in a cw high pressure tunable CO₂ laser is discussed. Broadening of the tuning range has given us the opportunity to find seven new absorption lines of SF₆ near the transition P(20) of the 00⁰1–10⁰0 band of the CO₂ laser.     

光学泵浦的锂分子激光

以可见染料激光泵浦锂分子,在高于900℃的蒸气温度下,获得了由理分子A¹∑_u⁺态跃迁到基态X¹∑_g⁺的位于874—912nm区的许多光泵激光输出。谐振腔使输出信号增强约9倍。对部分激光跃迁的振转量子数作了标识。 关键词：     

Resonance Raman scattering from amorphous As2S3

Resonance Raman scattering from amorphous As₂S₃, obtained by temperature tuning the band edge through the He-Ne 6328 Å laser line, is reported.