Journals >Chinese Journal of Lasers
Contents
1998
Volume: 25 Issue 8
20 Article(s)
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Research Article
Injection of Ions Produced by Laser Ablation in an Ion Trap
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The velocities and kinetic energies of laser ablated carbon cluster ions injected into an RF trap are measured. The relative trapping efficiencies of these cluster ions are given. The results may be helpful for further research of cluster ions in the RF trap.The velocities and kinetic energies of laser ablated carbon cluster ions injected into an RF trap are measured. The relative trapping efficiencies of these cluster ions are given. The results may be helpful for further research of cluster ions in the RF trap..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 689 (1998)
Laser Coherent Control of Molecular Vibration States and Transitions
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The idea of coherently synthesizing special superposition states with lasers is presented. Aiming directly at XY 2 type molecules, we identificated that it is possible to synthesize local mode vibrations using lasers. We calculated the transition probability between the superposition states and a bared state, and foundThe idea of coherently synthesizing special superposition states with lasers is presented. Aiming directly at XY 2 type molecules, we identificated that it is possible to synthesize local mode vibrations using lasers. We calculated the transition probability between the superposition states and a bared state, and found that this probability is coherent and also controllable by using external laser fields..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 693 (1998)
The Influence of Annealing Treatment on the Refractive Index Profiles of Ion-implanted Lithium Niobate Planar Waveguides
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
We have studied the influence of different annealing conditions on refractive index profiles of He and H ions implanted lithium niobate planar waveguides. After annealing treatment with different times and different temperatures the dark modes of both kinds of waveguides are measured by using a prism coupling method. TWe have studied the influence of different annealing conditions on refractive index profiles of He and H ions implanted lithium niobate planar waveguides. After annealing treatment with different times and different temperatures the dark modes of both kinds of waveguides are measured by using a prism coupling method. The refractive index profiles of both waveguides before and after annealing treatment are given. The results show that both He and H ions implantations result in the decrease of the ordinary refractive index in barriers, but in the region of guides the extraordinary refractive index increases. Annealing treatment influences the ordinary refractive index profiles obviously, but under 400°C the annealing treatment alomost has no influence on the extraordinary refractive index profiles..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 699 (1998)
Effect of Laser Random Phase Noise on the Fiber-optic Sensor System
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The output power spectrum of a sensor system with n-sensors arranged in parallel has been analyzed theoretically and calculated in detail. The calculated result shows that the noise of the sensors system mainly came from laser random phase noise and the noise level was mainly decided by the coherence time of the laser The output power spectrum of a sensor system with n-sensors arranged in parallel has been analyzed theoretically and calculated in detail. The calculated result shows that the noise of the sensors system mainly came from laser random phase noise and the noise level was mainly decided by the coherence time of the laser diode. The theoretical calculation agrees with our observation very well..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 703 (1998)
Laser Photothermal Scattering Technique to Measure Thermal Diffusivity of Opaque Materials
[in Chinese], and [in Chinese]
A method to measure thermal diffusivity of opaque materials by a laser photothermal scattering technique is introduced in this paper. The thermal diffusivity can be fitted by amplitude and phase of the sample photothermal signal at different frequencies and the thermal diffusivity of nanometer Al2O3 at different sinterA method to measure thermal diffusivity of opaque materials by a laser photothermal scattering technique is introduced in this paper. The thermal diffusivity can be fitted by amplitude and phase of the sample photothermal signal at different frequencies and the thermal diffusivity of nanometer Al2O3 at different sintering temperatures is measured by the method..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 707 (1998)
Shenguang-Target Pointing System
[in Chinese], [in Chinese], and [in Chinese]
This paper introduces the principle and structure of the Shenguang Ⅱ target pointing system used in inertial confinement fusion experiment. We use a space coordinate method to position and point the target and align the laser beam, and use an off-focus radius-finding technique to find the laser focus. The experimental This paper introduces the principle and structure of the Shenguang Ⅱ target pointing system used in inertial confinement fusion experiment. We use a space coordinate method to position and point the target and align the laser beam, and use an off-focus radius-finding technique to find the laser focus. The experimental results are given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 711 (1998)
Computer Simulation of Phase Contrast Alignment of Birefringent Axes in Panda Fiber of Matching Refractive-index
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, the simulated mathematical models of the panda fiber of matching refractive-index (MRI) were given through the structure of the fiber and the physics principles of phase contrast. Computer simulation of phase contrast alignment of birefringent axes (BA) in the panda fiber was done. Simulated mathematicalIn this paper, the simulated mathematical models of the panda fiber of matching refractive-index (MRI) were given through the structure of the fiber and the physics principles of phase contrast. Computer simulation of phase contrast alignment of birefringent axes (BA) in the panda fiber was done. Simulated mathematical models include several physics principles, e.g., distribution of stress-induced refractive index in the panda fiber of MRI, phase contrast, and image error of optical fiber around the observation plane of the objective lens. Computer simulation gave the optical intensity distinguishing profile in phase contrast to align BA in the panda fiber of MRI. The simulated profiles fit well with experimental ones. The technique has been used in experiments and the resolving power was less than two degrees..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 715 (1998)
Laser Manufacturing
Semi-analytical Calculation of the Laser Beam Induced Transient Temperature Field in the Solids (Including the Partial Beam Irradiated Cases)
[in Chinese], [in Chinese], and [in Chinese]
This article deals with the problem of semi-analytical calculation of the laser beam induced transient temperature field in the solids including the partical beam irradiated peroids. The experimental results are given.This article deals with the problem of semi-analytical calculation of the laser beam induced transient temperature field in the solids including the partical beam irradiated peroids. The experimental results are given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 753 (1998)
Research of Apoptotic Mice Thymocytes in Vitro Generated by He-Ne Laser Irradiation
[in Chinese], [in Chinese], and [in Chinese]
An instant elevation in intracellular Ca 2+ concentration ([Ca 2+] i) appears significant after the irradiation of cells with a He-Ne laser. Studies using various cell types have demonstrated changes in DNA fluorescence that were attributable to a process of the apoptosis. The apoptosis is activation of an endonucleaseAn instant elevation in intracellular Ca 2+ concentration ([Ca 2+] i) appears significant after the irradiation of cells with a He-Ne laser. Studies using various cell types have demonstrated changes in DNA fluorescence that were attributable to a process of the apoptosis. The apoptosis is activation of an endonuclease, which has relation to the intracellulle [Ca 2+] i. The study has discovered an increase of the apoptosis of the mice thymocytes following the irradiation time elongation with the He-Ne laser. The apoptosis shows an elevation of the subdiploid peak in a histogram..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 759 (1998)
Effect of Double-layer Precoating on the Laser Cladding Ceramal Layer
[in Chinese], [in Chinese], and [in Chinese]
The ceramal layer on the surface of mild steel was cladded by using a double-layer precoating method. The composition, microstructure, and hardness of the ceramal layer were analysed with the help of EPMA, XRD and a microhardness measuring instrument. The results show that a more uniform microstructure and higher hardnThe ceramal layer on the surface of mild steel was cladded by using a double-layer precoating method. The composition, microstructure, and hardness of the ceramal layer were analysed with the help of EPMA, XRD and a microhardness measuring instrument. The results show that a more uniform microstructure and higher hardness were obtained in the ceramal layer, and there are no porosities and cracks in it..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 763 (1998)
Laser Physics
Analysis of the Temporal Performance of a Gain-switched Four-level Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
This article reports a simple theoretical model developed for the temporal performance of a short laser pulse pumped, gain-switched, four-level laser system. The model is based on the rate-eqations of four-level systems and some practical physics conditions. From the model, we obtain some analytical relationships betweThis article reports a simple theoretical model developed for the temporal performance of a short laser pulse pumped, gain-switched, four-level laser system. The model is based on the rate-eqations of four-level systems and some practical physics conditions. From the model, we obtain some analytical relationships between the build-up time, pulse width of the output laser pulse and the pumping energy and energy density. The rationality of the model is analyzed according to the expermental results..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 673 (1998)
Analysis of Higher Harmonics for FEL with a Novel Electrostatic Wiggler
[in Chinese], [in Chinese], and [in Chinese]
The spontaneous emission spectrum and higher harmonic gain of a relativistic electron in a novel electrostatic wiggler are discussed. The results forms are similar to those in the linear polarized magnet wiggler. It should be pointed out that when there exists an axial electrostatic field, the higher harmonics may be gThe spontaneous emission spectrum and higher harmonic gain of a relativistic electron in a novel electrostatic wiggler are discussed. The results forms are similar to those in the linear polarized magnet wiggler. It should be pointed out that when there exists an axial electrostatic field, the higher harmonics may be generated..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 677 (1998)
Observation and Elimination of Chaos in an Intracavity Frequency-doubled Nd:YAG Laser Pumped by Krypton Flashlamp
[in Chinese], and [in Chinese]
In this paper, base on analysing the characters between the diode-pumped and krypton flashlamp-pumped lasers, we put forword a study of instability and chaos and of the elimination of chaos in krypton flashlamp-pumped intracavity frequency-doubled Nd:YAG lasers. Theoretical analyses and experimental apparatus are givenIn this paper, base on analysing the characters between the diode-pumped and krypton flashlamp-pumped lasers, we put forword a study of instability and chaos and of the elimination of chaos in krypton flashlamp-pumped intracavity frequency-doubled Nd:YAG lasers. Theoretical analyses and experimental apparatus are given, the results of chaotic laser radiation and its power spectra obtained through numerical calculation and experimental measurement are presented. By putting a Nd:YAG color center crystal in the resonator, the stable periodic laser radiation is attained and the elimination of chaos is realized..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 681 (1998)
A Near-infrared Tunable Injection-seeded Optical Parametric Oscillator
[in Chinese], [in Chinese], and [in Chinese]
We have demonstrate a tunable near-infrared KTP optical parametric oscillator that uses the CW Ti:sapphire laser output as the injection seeder and the second harmonic of a Q-switched Nd:YAG as the pump source. The linewidth of the OPO was less than 0.02 nm and the OPO can be tuned from 760 to 830 nm. The threshold of We have demonstrate a tunable near-infrared KTP optical parametric oscillator that uses the CW Ti:sapphire laser output as the injection seeder and the second harmonic of a Q-switched Nd:YAG as the pump source. The linewidth of the OPO was less than 0.02 nm and the OPO can be tuned from 760 to 830 nm. The threshold of the seeder′s power density was about 0.5 W/cm2..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 686 (1998)
Neutral Doped Aluminum Clusters: Generation under Special Source Conditions and their Photoionization Mass Spectra
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
We report photoionization TOF mass spectra which contain simultaneously Al n (n=7～14), Al nC m (m=1,2), Al n(H 2O) m (m=1,2) and Al nO m (m=1,2,…,7) series, and discuss the main features of each series as well as their evolution with the relative concentrations of the dopants/reactants. An explanation is put forward toWe report photoionization TOF mass spectra which contain simultaneously Al n (n=7～14), Al nC m (m=1,2), Al n(H 2O) m (m=1,2) and Al nO m (m=1,2,…,7) series, and discuss the main features of each series as well as their evolution with the relative concentrations of the dopants/reactants. An explanation is put forward to analyse the magic numbers of Al nC and Al nC-. Also, formation mechanism of the aluminum-oxygen mixed clusters, Al 5O 3, Al 7O 4 and Al 9O 7, is suggested..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 722 (1998)
Application of Paraxial Riemannian Geometrical Optics: Self-focusing of Light Beams
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Base on the HMO (hydrodynamic model of optics), self-focusing propagation properties are simulated by numerical calculations. The results agree well with the experiment.Base on the HMO (hydrodynamic model of optics), self-focusing propagation properties are simulated by numerical calculations. The results agree well with the experiment..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 727 (1998)
Nonequilibrium Electron Relaxation in the Thin Film Stimulated by Femtosecond Pulse Laser
[in Chinese], and [in Chinese]
The pump-probe method was used for measuring the transient change of optical transmissivity of a composite thin film Au-Ba-O which was stimulated by a femtosecond pulsed laser. A phenomenon was observed that the optical absorption in the thin film rapidly increased and then recovered in a few picoseconds. Optical relaxThe pump-probe method was used for measuring the transient change of optical transmissivity of a composite thin film Au-Ba-O which was stimulated by a femtosecond pulsed laser. A phenomenon was observed that the optical absorption in the thin film rapidly increased and then recovered in a few picoseconds. Optical relaxation is a process in which nonequilibrium electrons, excited by laser pulses and originating from Au ultrafine particles, return to the equilibrium state. In this paper, a theoretical value of the electron-phonon coupling constant g of Au ultrafine particles in the composite thin filim was given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 733 (1998)
The Chirp Induced by Third-order Dispersion in a Single-mode Fiber
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Taken into account the third-order dispersion in a single-mode fiber by means of Fourier-transform algorithm, an analytic expression of chirp is obtained. The results show that chirp is nonlinear and has extreme value near the center of the pulse and depends on the initial chirp.Taken into account the third-order dispersion in a single-mode fiber by means of Fourier-transform algorithm, an analytic expression of chirp is obtained. The results show that chirp is nonlinear and has extreme value near the center of the pulse and depends on the initial chirp..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 739 (1998)
Study of the Properties of the Shock Wave Induced by High-power Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Using a new piezoelectricity gauge of insulation film and combined-high-polymer of a short rise time and wide linear response range, together with a PIN optoelectric tube and PHILIPS PM 3320A oscilloscope, the real-time measurement of pressure of the laser-induced shock wave is realized. Based on this technology, the pUsing a new piezoelectricity gauge of insulation film and combined-high-polymer of a short rise time and wide linear response range, together with a PIN optoelectric tube and PHILIPS PM 3320A oscilloscope, the real-time measurement of pressure of the laser-induced shock wave is realized. Based on this technology, the propagation velocity and attenuation coefficient of the laser-induced shock wave in aluminum are obtained. The average propagation velocity of the laser-induced shock wave in aluminum is 6.38×10 3m/s. The attenuation of peak pressure of the laser-induced shock wave in Al is an exponential function: P(x)=0.48exp(-0.14x)..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 743 (1998)
Optical Properties of Pyrromethene 567 Doped Xerogels
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Laser dye pyrromethene 567 molecules were successfully incorporated into organically modified silicate (Ormosil) matrices by the sol-gel technique. The fluoresence properties of dye-doped Ormosil were studied in the present paper. Using these new materials in solid-state dye lasers, laser oscillation has been achieved Laser dye pyrromethene 567 molecules were successfully incorporated into organically modified silicate (Ormosil) matrices by the sol-gel technique. The fluoresence properties of dye-doped Ormosil were studied in the present paper. Using these new materials in solid-state dye lasers, laser oscillation has been achieved near 563nm with the slope efficiency of 52% from pyrromethene 567 doped SiO 2-Ormosil pumped by a frequency-doubled radiation from a Q-switched Nd:YAG laser. The laser wavelength is tunable over 30nm (545.6～578.8nm). The laser output energy has only a 10% reduction after 2.7×10 4 pulses at a pump repetition rate of 1Hz and a pump intensity of 1 J/cm2..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 8, 748 (1998)
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