半导体泵浦铷蒸气激光实现线偏振基模输出

采用2400 1/mm的平面光栅搭建Littrow外腔压窄半导体激光器输出激光线宽,获得中心波长可调的线宽0.16 nm的半导体激光作为铷蒸气激光的泵浦源.实验中,使用斩波器将泵浦光变为脉宽1 ms,重复频率100 Hz的重复脉冲形式,聚焦进长度为8 mm的铷蒸气泡,泡内充入79 kPa甲烷作为缓冲气体.进入铷蒸气泡的泵浦光峰值功率为1.84 W时,控制铷泡温度在125℃,获得了峰值功率17.5 mW的基模线偏振铷激光输出.     

半导体泵浦铷蒸气激光器国内首次出光

采用体光栅对商用线阵半导体激光器进行线宽压缩,得到线宽0.1 nm、中心波长780.2 nm、最高连续输出功率80 W的泵浦激光输出。为了降低热效应,通过外加斩波器将泵浦光转化为脉冲模式,脉宽440 μs,占空比为1∶5。采用长度为5 mm的铷金属饱和蒸气作为增益介质,并在常温下充入33 kPa乙烷和47 kPa氦气,进行了出光实验。在泵浦峰值功率35.4 W,铷吸收池温度120 ℃时,得到峰值功率600 mW的795 nm铷激光输出,斜率效率为1.7%。     

半导体泵浦铷蒸气激光器国内首次出光北大核心CSCD

采用体光栅对商用线阵半导体激光器进行线宽压缩,得到线宽0.1nm、中心波长780.2nm、最高连续输出功率80W的泵浦激光输出。为了降低热效应,通过外加斩波器将泵浦光转化为脉冲模式,脉宽440μs,占空比为1∶5。采用长度为5mm的铷金属饱和蒸气作为增益介质,并在常温下充入33kPa乙烷和47kPa氦气,进行了出光实验。在泵浦峰值功率35.4W,铷吸收池温度120℃时,得到峰值功率600mW的795nm铷激光输出,斜率效率为1.7%。     

半导体泵浦铯蒸气实现激光输出

采用线宽0.26 nm的Littrow外腔巴条半导体激光器泵浦增益长度8 mm缓冲气体为80 kPa甲烷的铯（Cs）蒸气室,在Cs蒸气室温度120 ℃时,我们获得了394 mW的894.6 nm线偏振Cs蒸气激光,光光效率7.4%,斜率效率11.2%,阈值功率为1.72 W。     

半导体泵浦铯蒸气实现激光输出

采用线宽0.26nm的Littrow外腔巴条半导体激光器泵浦增益长度8mm缓冲气体为80kPa甲烷的铯(Cs)蒸气室,在Cs蒸气室温度120℃时,我们获得了394mW的894.6nm线偏振Cs蒸气激光,光光效率7.4%,斜率效率11.2%,阈值功率为1.72W。     

铷原子热蒸气中强非线性效应产生激光模式图样的实验研究

研究了具有高斯横向分布的连续激光束单次通过铷原子蒸气后,在近共振附近铷原子蒸气中,由强的非线性克尔效应导致激光分裂成细丝的现象,并且这些细丝的衍射图样在远场通过相干叠加,可以形成具有规则结构的斑图模式.实验上研究了输入光功率,铷泡温度和抽运激光频率相对于⁸⁵Rb原子D₂线的不同失谐位置等因素对斑图模式的影响.由于铷原子的超精细能级结构,在铷原子蒸气中同时存在与三阶非线性效应相关的四波混频现象,通过扫描探测光的频率同时观察到具有斯托克斯和反斯托克斯光子的拉曼增益现象. 关键词： 铷原子蒸气 克尔效应 自聚焦 斑图     

二极管抽运铷蒸气激光的物理特性

结合激光微观动力学和热传学,充分考虑到发射激光时的各能级粒子数和热力学分布特性,建立了用于分析二极管抽运铷金属蒸气激光物理特性和增益腔内的温度分布模型,得到了抽运功率和激光输出、光-光转换效率及各物理参数之间的关系,分析了有效提高抽运能量吸收的具体措施,揭示了2P3/2和2P1/2两个精细能级之间的集居数弛豫对半导体抽运碱金属蒸气激光器(DPAL)物理特性的影响。结果表明：在设计不同用途DPAL时,必须要综合考虑各种因素,以确定相应的最佳结构参数。     

半导体泵浦铷蒸气激光器出光实验

针对中心波长780 nm的商用连续波半导体激光器,使用斩波器将连续激光变为脉冲输出形式,用2400 line/mm的平面全息光栅搭建Littrow外腔将线宽压窄至0.2 nm以下。采用透镜组对线宽压窄后的半导体激光进行光束整形,半导体激光经线宽压窄和光束整形后,经透镜聚焦进长约8 mm的铷蒸气泡进行半导体泵浦碱金属激光实验。首次出光得到17.5 mW的基模线偏振铷激光;在最新的改进实验中,半导体泵浦铷激光输出功率已达到2.8 W。     

半导体泵浦铷蒸气激光器出光实验

针对中心波长780 nm的商用连续波半导体激光器,使用斩波器将连续激光变为脉冲输出形式,用2400 line/mm的平面全息光栅搭建Littrow外腔将线宽压窄至0.2 nm以下。采用透镜组对线宽压窄后的半导体激光进行光束整形,半导体激光经线宽压窄和光束整形后,经透镜聚焦进长约8 mm的铷蒸气泡进行半导体泵浦碱金属激光实验。首次出光得到17.5 mW的基模线偏振铷激光;在最新的改进实验中,半导体泵浦铷激光输出功率已达到2.8 W。     

Distortions of laser pulses in neodymium atomic vapor

An experiment on the simulation of the conditions for propagation of laser pulses in dense neodymium atomic vapor is proposed for the development of a technological setup for the laser separation of the ¹⁵⁰Nd isotope from a kilogram sample of natural mixture. The comparison of waveforms of laser pulses in the presence and in the absence of absorption shows that the absorption predominantly takes place at the leading edge of the pulse. The experimental distortion of the waveform is related to the saturation of absorption. The effect is well described using the calculations based on the formalism of the rate equations.     

Ultrafast optical spectroscopy of spectral fluctuations in a dense atomic vapor

Transient four-wave mixing experiments with 100 fs pulses in a dense potassium vapor probe the electronic energy fluctuations that lead to optical decoherence. Echo-peak shift experiments yield a biexponential two-time correlation function of energy level fluctuations. Molecular dynamics simulations show that the slow component is a many-body excitonic contribution arising from long-range resonant interactions. The decay of the correlation function occurs on comparable time scales in theory and experiment.     

Selective reflection of a laser beam from a dilute rubidium vapor

We study the selective reflection of the laser beam from rubidium atomic vapor at the D₂ line (wavelength λ = 780 nm) at different atomic densities. We use a tunable free-running diode laser. We observed a measurable signal at a low atomic density N when the mean distance between resonance atoms reached two wavelengths. In our experiment, the dimensionless parameter N ^1/3 λ varied from 0.5 to 2.8. The reflectivity increased with density monotonically. It is interesting to perform experiments when the parameter N ^1/3 λ ≪ 1.     

用于铷蒸气激光泵浦的窄线宽阵列半导体激光器

在激光二极管LD泵浦铷蒸气激光器中,窄线宽半导体激光是实现铷蒸气激光高效率输出的关键技术之一。基于体布拉格光栅（VBG）外腔技术,实现了40 W功率0.14 nm线宽的780 nm激光输出。采用半导体制冷片（TEC）控制VBG温度,使得该激光器空气中波长可从779.35 nm调谐至780.10 nm,可用于铷蒸气激光的高效泵浦。     

Sources of atomic vapor for laser isotope separation

Conclusions Thus, our experimental investigations of the methods of obtaining a vapor of neutral atoms of the refractory and chemically active rare element (Gd) have shown that both investigated methods — electron-beam evaporation and cathode sputtering — are promising. The fact that the levela ⁹D₅ is equally singled out in the electron-beam evaporation and in the cathode sputtering is evidence of the decisive importance of the processes of establishment of the distribution of the populations over the sublevels of the ground state of the evaporated atoms. It is obvious here that the determination of the properties of this distribution for other elements calls for investigations similar to those described above.The question of the choice of source of neutral atoms should be solved separately for each chosen laser isotope separation scheme.Translated from Trudy Ordena Lenina Fizicheskogo Instituta im. P. N. Lebedeva Akademii Nauk SSSR, Vol. 114, pp. 24–37 (1979)     

用于铷蒸气激光泵浦的窄线宽阵列半导体激光器

在激光二极管LD泵浦铷蒸气激光器中,窄线宽半导体激光是实现铷蒸气激光高效率输出的关键技术之一。基于体布拉格光栅（VBG）外腔技术,实现了40 W功率0.14 nm线宽的780 nm激光输出。采用半导体制冷片（TEC）控制VBG温度,使得该激光器空气中波长可从779.35 nm调谐至780.10 nm,可用于铷蒸气激光的高效泵浦。     

Diode laser spectrally fixed at an atomic absorption line

A simple all-optical technique for fixing the spectrum of the output from semiconductor laser at a chosen absorption atomic line is realized and studied. The technique, which is not of a laser locking type, uses a conventional diode laser without any influence on its operation. For implementation of the technique, the diode laser output is fed to a modified Michelson interferometer, and controllable disturbing of phase and amplitude correlation between the interfering beams in the two arms of the interferometer is achieved by frequency scanning through a contour of a reference absorption line of a substance introduced in one of the arms of the interferometer. It is shown both by experiment and theory that, under properly chosen conditions, the spectrum of the obtained light is fixed at the atomic line and has a linewidth comparable to the linewidth of the used absorption line.     

Self-rotation of optical polarization in rubidium vapor

We present an experimental and theoretical study of self-rotation of optical polarization in a rubidium vapor.The atomic vapor is placed in a magnetic shielding cavity to suppress the Faraday rotation effect.In our experiment,Doppler-free spectroscopy configuration is used,and F = 2 → F ’ = 3 transition of 87Rb D2 line is chosen.We observe self-rotation of optical polarization effect at different pump light ellipticities.A theoretical analysis is then provided based on the experimental conditions.Theoretical simulation and experimental results are in good agreement.     

Methods and evaluation of frequency aging in distributed-feedback laser diodes for rubidium atomic clocks

Distributed-feedback laser diodes emitting at 780?nm have been evaluated, with respect to the aging of the injection current required for reaching the rubidium D2 resonance line. Results obtained for lasers operating in air and in vacuum for 9 months are reported. When operated at constant temperature, the laser current required for emission at the wavelength of the desired atomic resonance is found to decrease by 50 to 80?μA per month. The impact of this result on the lifetime and long-term performances of laser-pumped rubidium atomic clocks is discussed.     

铷原子蒸汽中的光偏振旋转效应

对铷原子(⁸⁷Rb)蒸汽中的法拉第旋转、光学偏振自旋转以及二者的叠加旋转效应进行了理论和实验研究.对三种情况下旋转现象建立了简单而有效的理论模型. 实验中把铷原子泡置于自行设计的磁屏蔽腔内, 以屏蔽地磁场的影响.实验选择⁸⁷Rb F=2→F'=3能级D2跃迁线并采用零多普勒光谱 实验结构消除多普勒展宽对实验光谱的影响. 实验中分别观测到了三种旋转现象,实验结果与理论模拟结果非常符合.