LD端抽运平直腔Nd:YVO4固态激光器的输出功率特性研究

对LD端抽运平直腔Nd:YVO₄固态激光器输出功率特性受激光器内在诸因素(热透镜效应、腔长、激活孔径等)的制约关系进行了研究.并用传播圆-变换圆图解分析方法给出了合理的解释，同时，对进一步提高其输出功率特性指出了方向. 关键词： 固体激光器 热透镜 变换圆 平直腔     

二维随机激光器的模式选择及阈值与饱和特性

基于将Maxwell方程与四能级原子系统速率方程相结合而建立起随机激光时域理论，并利用有限时域差分法，研究了二维随机介质中激光模式的输出特性与介质尺寸、外形及抽运速率等参数的关系.结果表明，与传统激光模式相似，随机激光模式的强度随抽运速率的变化不仅具有阈值特性，而且具有饱和特性.基于模式特性对介质及抽运参数的依赖关系，提出了二维随机激光器的选模方式，在很大程度上不同于传统激光器的选模方式. 关键词： 随机激光器 模式选择 无序介质中的光学特性     

Active Q-switching of the Alexandrite laser

An alexandrite-laser rod was actively Q-switched in the transversal fundamental mode at λ = 758 nm with an double crystal KD^*P Pockels cell. Pulse width, pulse energy and optical pulse delay (the build-up time of the photon field in the resonator) were measured as functions of pumping energy, rod temperature and reflectivity of the output coupling mirror. As the laser gain of alexandrite strongly depends on temperature, the pulse width and pulse energy were also investigated as functions of the temperature of the active material. A comparison of experimental data with theory was made.     

Physical Analysis of a Possibility to Reach the 1.30-μm Emission from the GaAs-Based VCSELs with the InGaAs/GaAs Quantum-Well Active Regions and the Intentionally Detuned Optical Cavities

Physical aspects of an operation of the GaAs-based InGaAs/GaAs quantum-well (QW) VCSELs with the intentionally detuned optical cavities have been considered in the present paper using the comprehensive three-dimensional self-consistent optical–electrical–thermal-gain simulation. In GaAs-based structures, very good DBR resonator mirrors and a very efficient methods to confine radially both the current spreading and the electromagnetic field with the aid of oxide apertures may be applied. It has been found using the above simulation that even currently available immature technology enables manufacturing the above devices emitting radiation of wavelengths over 1.20 μm. In particular, while the room-temperature 1.30-μm lasing emission is still beyond possibilities of the InGaAs/GaAs QW VCSELs, these structures may offer analogous 1.25-μm emission, especially for the high-power and/or high-temperature operation.     

Low-threshold interband cascade lasers operating above room temperature

Mid-IR type-II interband cascade lasers were demonstrated in pulsed mode at temperatures up to 325 K and in continuous mode up to 200 K. At 80 K, the threshold current density was 8.9 A/cm² and a continuous wave output power of 140 mW/facet was obtained.     

激光二极管抽运的GaAs被动Q开关Nd：YVO4激光器

利用固体可饱和吸收体砷化镓（GaAs）作为被动调Q元件，实现了激光二极管抽运平－凹腔掺钕钒酸钇（Nd:YVO4）激光调Q运转，详细测量了砷化镓被动调QNd:YVO4激光输出特性，获得脉宽15ns，重复频率470kHz，光束质量M^2=1.31的激光输出，调Q激光运转阈值为500mW，并数值求解了砷化镓被动调Q速率方程，讨论了被动调Q机理以及调Q脉冲宽度和脉冲重复频率对抽运速率的依赖关系，理论计算结果与实验结果相一致。     

10-GHz Optical Comb in L-Band Region With Brillouin/Erbium-Doped Fibre Laser

A multiwavelength Brillouin/erbium fibre laser (BEFL) which operates in the long wavelength (L-band) region is demonstrated for potential applications in an L-band wavelength division multiplexing (WDM) communication system. The laser configuration consists of a long erbium-doped fibre to enable L-band amplification where two 3-dB couplers take a portion of the generated BEFL signal and re-inject it into the single mode fibre to seed a cascaded BEFL line in the same direction as the first BEFL line. A stable and strong laser comb of up to five lines with 10-GHz spacing has been obtained with a Brillouin pump (BP) of 9.2 mW and a 980 nm pump of 92 mW. The BEFL has shown a broad tuning range with a tuning characteristic for line #1 which is flat over a range greater than 9.9 nm.     

Precise measurement of hyperfine structure in the state of Rb

We demonstrate a technique to measure hyperfine structure using a frequency-stabilized diode laser and an acousto-optic modulator locked to the frequency difference between two hyperfine peaks. We use this technique to measure hyperfine intervals in the 5 P _3/2 state of ⁸⁵Rb and obtain a precision of 20 kHz. We extract values for the magnetic-dipole coupling constant A = 25.038(5) MHz and the electric-quadrupole coupling constant B = 26.011(22) MHz. These values are a significant improvement over previous results. Received 6 March 2003 Published online 15 April 2003     

多棒串接固体激光器谐振腔的研究

运用矩阵光学的方法对多棒串接固体激光器的谐振腔参数及其在平平腔时的热稳条件进行了研究，并计算了六棒串接平平腔固体激光器的稳定区.结果证明：多棒串接固体激光器的稳定区和非稳区相互间隔，在平平腔总腔长、激光棒数量n和棒间距L一定的条件下，当采用对称结构时(L₁=L₂)，则谐振腔的每段稳定区均达到最大；且只要 平平腔满足L₁=L₂=L/2以及热焦距f在大于某个下限值f_m时，稳定性条件01< 关键词： 多棒串接固体激光器 稳定区 热稳条件     

类锂铝复合机制产生X光激光的等离子体状态

本文从速率方程出发,讨论了类锂铝复合等离子体的激发态结构,衰减常数,反转率和小信号增益等表征介质增益特性的物理量以及它们随电子温度,电子密度和光子逃逸几率的变化。找到了进行类锂铝离子通过复合机制产生X光激光设计应创造的等离子体状态目标区域。还讨论了这些物理量随原子序数变化的定标律。