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971.
本文从激光增强电离光谱的速率方程和LEI光谱加宽理论出发,得到LEI光谱信号和光谱轮廓的表达式,在紫外区测得铕的三条LEI谱线。并用计算机模拟光谱的方法给出这三条谱线的轮廓,与实验所得的谱图一致。 相似文献
972.
Ding Wang 《Optics Communications》2006,267(1):79-82
A true color stereoscopic hologram is made with one-wavelength laser. Under illuminating incandescent lamp, a true color stereoscopic image can be seen from the hologram. A diffused reference light and a project object light are used in the recording of the hologram. The three primary color images of natural scenery are encoded on a white-and-black film. With the help of the encoded film, a true color hologram is recorded on a plate by single exposure and a true color stereoscopic by two exposures. The simplification of this method is apparent. Further more, it largely decreases the scattering noise of the hologram and averts the problem of color lack fidelity of the holographic image. 相似文献
973.
A.A. Demidovich A.S. Grabtchikov V.A. Lisinetskii V.A. Orlovich 《Optics Communications》2006,263(1):52-59
The results of experimental and theoretical investigations of passive Q-switch Raman microchip lasers based on Nd3+:LSB active medium and Ba(NO3)2 Raman crystal are presented. It has been demonstrated that intracavity Raman conversion in the microchip lasers is a simple and efficient method, capable of delivering high power pulses with sub-100 ps duration. Intracavity generation of the 1st Stokes pulses with duration from 180 down to 48 ps and a peak power of 48 kW has been performed and studied. High peak power and short duration of the 1st Stokes pulses in microchip laser with Ba(NO3)2 Raman crystal allows to easily perform extracavity harmonic generation and frequency sum mixing in LBO, BBO, and KTP crystals with discrete-tunable wavelength from ∼1200 down to ∼240 nm. We have developed a generalized model of Q-switched Raman microchip lasers, that takes into account spatial inhomogeneity of pump, laser, and Stokes beams, thermalization within the upper and lower multiplets of activator ions in laser medium, and saturable absorber bleaching and recovery. For the microchip lasers with different saturable absorbers, the model achieves very good agreement with the presented experimental results in a wide range of pump powers. 相似文献
974.
M. Bernardini F. D''Amato M. Giorgi S. Marchetti 《International Journal of Infrared and Millimeter Waves》1989,10(1):31-41
Generally the quantum efficiency of FIR Raman generation in molecular gases is below the theoretical value. This disagreement is particularly evident in Raman scattering from pulsed sources with short pulse length, when the vibrational saturation limits the power conversion. Other nonlinear processes can overcome this saturation, but they require a very intense pump power for too short a time to use the FIR radiation in high sensitive experiments with heterodyne detection. This is the case, for instance, of RFWM. In this work we describe the experimental conditions to achieve a high efficiency 90 micron Raman conversion in ammonia, with both short and long pulses. 相似文献
975.
S.C. Snyder G.D. Lassahn 《Journal of Quantitative Spectroscopy & Radiative Transfer》2007,107(2):217-225
Direct gas temperature and gas velocity measurements made in the exit plane of a subsonic argon-hydrogen thermal plasma jet from high-resolution lineshape analysis of laser light scattered by the plasma are reported. The lineshapes are in general a superposition of the ion feature of the Thomson-scattered light and the lineshape of Rayleigh scattered light. In the center of the jet Thomson scattering dominates while at larger radii Rayleigh scattering dominates. Because of the complexity of the lineshapes of light scattered by multicomponent plasmas, only those that are predominantly due to Thomson scattering can in practice be analyzed for gas temperature. Gas velocity can be determined from the Doppler shift of the lineshapes relative to the frequency of the incident laser if the velocity is greater than about 50 m s−1. The maximum gas temperature measured was 14,500 K±5%. The maximum gas velocity measured was 1100 m s−1±3%. Temperature values and the radial velocity profile are compared with those previously obtained from a subsonic all-argon plasma jet operated under similar conditions. 相似文献
976.
用激光溅射 -分子束技术研究了Cu等离子体与乙腈团簇的气相反应 .观察到Cu+ (CH3 CN) n、CH2 CN+ (CH3 CN) n、H+ (CH3 CN) n 和CH3 CHCN+ (CH3 CN) n 四个种类的团簇离子 .考察了等离子体作用于脉冲分子束的不同位置 ,对团簇产物的种类和尺寸大小的影响 .实验结果表明 ,Cu+ (CH3 CN) n 是由Cu+ 与乙腈团簇直接缔合而成 ,CH2 CN+ (CH3 CN) n、H+ (CH3 CN) n 主要是激光等离子体中的电子与乙腈团簇碰撞电离产生的 ,而CH3 CHCN+ (CH3 CN) n 是由乙腈团簇离子内的离子 分子反应生成的 . 相似文献
977.
J.W.-H. Leung A.S.-C. Cheung K.D. Gibbs L.C. O’Brien 《Journal of Molecular Spectroscopy》2006,238(1):42-48
Vibrational bands belonging to the [15.0] 2Δ5/2-A2Δ5/2, [15.0] 2Δ5/2-X2Π3/2, and [15.0] 2Π3/2-X2Π3/2 electronic transitions of NiCl have been observed in the 14 000-16 000 cm−1 region. The [15.0] 2Δ5/2 and [15.0] 2Π3/2 states are identified for the first time. The observed bands have been recorded at high spectral resolution using several techniques, which include intracavity laser spectroscopy (ILS), Fourier transform emission spectroscopy (FTS), and laser induced fluorescence (LIF) spectroscopy. For the ILS absorption spectra, NiCl molecules were produced in a nickel hollow cathode operated with a small amount of CCl4. For the FTS emission spectra, excited NiCl molecules were produced in a King-type carbon tube furnace loaded with NiCl2 and heated to 1600 °C. In the LIF work, NiCl molecules were produced by reacting laser-ablated nickel with PCl3 seeded in argon. Detailed analysis of rotational transition lines indicates that the observed [15.0] 2Δ5/2 and [15.0] 2Π3/2 states are only separated by 10 cm−1 and are interacting with each other. Molecular constants for these newly observed electronic states are reported. 相似文献
978.
Theoretical analysis on phase-locking properties of a laser diode array facing an external cavity 总被引:2,自引:0,他引:2
Dan Lu Jianguo Chen Hua Yang Haibo Chen Xiaodong Lin Song Gao 《Optics & Laser Technology》2006,38(7):516-522
External coupling model has been used to describe the output field of a laser diode array (LDA) phase-locked with an external cavity. The analytical solution for the coupling matrix equation of the phase-locked system has been obtained. The dependencies of the threshold gain, gj of the system mode on the residue reflection of the front facet, rf and round trip external cavity lengths, L have been discussed. The working lengths of the external cavity for stably phase-locking the LDA of different residual reflectivities have been calculated. 相似文献
979.
980.