Journals >Chinese Journal of Lasers
Contents
2000
Volume: 27 Issue 10
20 Article(s)
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Research Article
Influence of the Length of SFL on the Measurement of Shape of Fizeau Interferometer
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this article, the influences of the length of SFL on the measurement of the shape of Fizeau interferometer is discussed. The 3-D diagram of the square difference of the nearest interferometric stripe radius changing with the length of SFL and the radius of measured surface, and the 2-D curve between the difference aIn this article, the influences of the length of SFL on the measurement of the shape of Fizeau interferometer is discussed. The 3-D diagram of the square difference of the nearest interferometric stripe radius changing with the length of SFL and the radius of measured surface, and the 2-D curve between the difference and the length at R→∞ are given. On the other hand, the relationship between the measured range and the length of SFL and the measured precision is also given. At last, through experiment the coinsidence between experimental and theoretical result is demonstrated..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 911 (2000)
Accurate Measurements of Nonlinear Refraction in the Second-order χ(2) Nonlinear Crystals
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on the spectrally resolved two-beam coupling, accurate measurements of the nonlinear index of the refraction of the nonlinear optical crystals of KDP, KTP, PPLN, BBO, LBO and LiIO3 are reported. The results were obtained using 100 fs 800 nm pulses from a Kerr-lens mode-locked Ti:sapphire laser oscillator.Based on the spectrally resolved two-beam coupling, accurate measurements of the nonlinear index of the refraction of the nonlinear optical crystals of KDP, KTP, PPLN, BBO, LBO and LiIO3 are reported. The results were obtained using 100 fs 800 nm pulses from a Kerr-lens mode-locked Ti:sapphire laser oscillator..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 917 (2000)
Optical Trapping and Manipulation of Microbe Using Laser Tweezers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
According to the physics mechanism of laser manipulating dialectrical particles, the biological samples can be trapped and moved by a highly focused laser beam. Some experimental results of laser manipulating for different kinds of microbe are discussed. The results show that the preculture of biological specimen is thAccording to the physics mechanism of laser manipulating dialectrical particles, the biological samples can be trapped and moved by a highly focused laser beam. Some experimental results of laser manipulating for different kinds of microbe are discussed. The results show that the preculture of biological specimen is the key step for realizing laser manipulating..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 921 (2000)
Holography and Information Processing
Study of Computer-generated Hologram Grating Scanner
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The equations of the reflective disk computer-generated grating scanner are presented. The grating scanner with a high diffraction efficiency was fabricated by a novel technique. The character of the grating scanner is discussed.The equations of the reflective disk computer-generated grating scanner are presented. The grating scanner with a high diffraction efficiency was fabricated by a novel technique. The character of the grating scanner is discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 898 (2000)
Implementation of Information Decomposing Using CGH and Its Application in Optical Image Encryption
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An information encryption method using CGH is presented in this paper. In this method, the encryption information is divided into two parts and recorded on two CGHs, respectively, the phase of wave recorded on each CGH has been coded according to the recording information and distributing randomly. When a single CGH isAn information encryption method using CGH is presented in this paper. In this method, the encryption information is divided into two parts and recorded on two CGHs, respectively, the phase of wave recorded on each CGH has been coded according to the recording information and distributing randomly. When a single CGH is reconstructed, no information will be observed, while two alignment combining CGHs are reconstructed, the original information will be observed in the interference patterns of the two reconstructed waves. Information can be read out only when two holograms are matched, which ensure hologram a high encryption ability..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 903 (2000)
Improving Confocal Scanning Imaging System Resolution by Using Apodization
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In confocal scanning imaging system, using apodization can improve the system resolution. The paper presents the principles. The experiments are done in a reflection mode fiber confocal scanning microscopy with the mask, the intensity response curves in transverse and axial direction of this system are given. A sharp sIn confocal scanning imaging system, using apodization can improve the system resolution. The paper presents the principles. The experiments are done in a reflection mode fiber confocal scanning microscopy with the mask, the intensity response curves in transverse and axial direction of this system are given. A sharp straight edge of a flat object is measured. The results demonstrate that an apodizated mask does not reduce the axial resolution while can improve the transverse resolution..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 907 (2000)
Laser Devices and Laser Physics
Experimental Study on Calcium Ion Self-terminating Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A calcium ion self-terminating laser has been achieved with high-repetition-frequency by longitudinal discharge stimulation. The maximum average laser power of 176 mW is obtained. Some parameters are measured and the characteristics are discussed.A calcium ion self-terminating laser has been achieved with high-repetition-frequency by longitudinal discharge stimulation. The maximum average laser power of 176 mW is obtained. Some parameters are measured and the characteristics are discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 877 (2000)
Laser Manufacturing
Enthalpy Solution of Conduction Phase Change During Laser Processing
[in Chinese], [in Chinese], and [in Chinese]
An axisymmetric model has been developed to simulate conduction phase change during laser processing based on enthalpy method. The spatial and temporal profile of the laser beam and the temperature dependent properties of the material have been taken into account in the model. A Gaussian beam and a flat beam are used, An axisymmetric model has been developed to simulate conduction phase change during laser processing based on enthalpy method. The spatial and temporal profile of the laser beam and the temperature dependent properties of the material have been taken into account in the model. A Gaussian beam and a flat beam are used, respectively, to simulate the interaction with iron as target and the results for vapor-liquid and liquid-solid interface evolutions and temperature field development in the material are obtained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 931 (2000)
Effects of Experimental Parameters on LSP
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The shock piezoelectrical wave, pressure wave and the pit′s depth were measured in the laser shock-processing experiment. The effects of confining medium and overlay on shock wave were discussed.The shock piezoelectrical wave, pressure wave and the pit′s depth were measured in the laser shock-processing experiment. The effects of confining medium and overlay on shock wave were discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 937 (2000)
Microstructure and Performance of the SiC/Stainless Steel Composite Coating Produced by Nd:YAG Laser Cladding
[in Chinese], and [in Chinese]
SiC reinforced iron matrix composite coatings have been successfully produced by using a 2 kW Nd:YAG laser on a 40Cr steel substrate, and microstructure analysis and performance testing of the coatings are carried out. There are two forms of SiC in the experiment: particle and fiber. By adjusting the adding content of SiC reinforced iron matrix composite coatings have been successfully produced by using a 2 kW Nd:YAG laser on a 40Cr steel substrate, and microstructure analysis and performance testing of the coatings are carried out. There are two forms of SiC in the experiment: particle and fiber. By adjusting the adding content of SiCp and of SiCf, evolution of SiC of different forms during laser cladding, existing forms of SiC in cladding layers and affection on hardness of cladding layers are studied. The results show that during laser cladding, SiC of different forms is decompounded partially; with the increasing of the SiC adding content, the quantity of un-melt SiC increases and hardness of cladding layers improves. Comparing the hardness of SiC particle reinforced coating with the SiC fiber reinforced coating, the reinforcing effecting of SiC fiber is higher; the main reasons bring hardness remarkable improvement are disperse reinforcement of un-melt SiC and propitiation FeSiC, and solution reinforcement of decompounded Si, C..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 941 (2000)
Influences of Additive SiO2 in Plasma Sprayed Ceramic Coatings and Subsequent Laser Remelting
[in Chinese], [in Chinese], and [in Chinese]
The influences of additive SiO2 in the plasma sprayed ceramic coatings and subsequent laser remelting have been investigated in this paper. The liquid-sintering effect of SiO2 is considerably obvious in the ceramic coating ZrO2of a high melting point, while this effect is not apparent in Al2O3 coating possessing a relaThe influences of additive SiO2 in the plasma sprayed ceramic coatings and subsequent laser remelting have been investigated in this paper. The liquid-sintering effect of SiO2 is considerably obvious in the ceramic coating ZrO2of a high melting point, while this effect is not apparent in Al2O3 coating possessing a relatively low melting point. During laser remelting, the additive SiO2 can not only reduce the cooling stress of the remelted layer in ZrO2coating, but also hinder the spreading of cracks. While in Al2O3 coating, in addition to the above effects, SiO2 can further make the grain-size distribution more uniform and form a continuous glass-like matter around the grain boundaries, thus the formation and spreading of cracks will be suppressed. As to TiO2, during laser remelting, it will react with Al2O3 transforming into TiAl2O5 that possesses a large anisotropic coefficient of expansion, thus it will lead to a big and asymmetrical stress and finally some cracks occur in the remelted layer..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 947 (2000)
Effect of Amorphous Structure in the Laser Clad Zone on Tribological Characteristics
[in Chinese], [in Chinese], and [in Chinese]
Using a 5 kW CO2 laser, a Ni-Cr-Al plasma coating on Al-Si alloy surface was remelted as a cladding layer. The microstructural analysis showed that there are some amorphous structures in the clad zone that co-exist with crystalline Ni3Al. A semi-quantitative method using DTA was used to determine the content of amorphoUsing a 5 kW CO2 laser, a Ni-Cr-Al plasma coating on Al-Si alloy surface was remelted as a cladding layer. The microstructural analysis showed that there are some amorphous structures in the clad zone that co-exist with crystalline Ni3Al. A semi-quantitative method using DTA was used to determine the content of amorphous structure in the zone. Wear tests of laser clad samples using different amorphous contents paired with grey cast iron were carried out under oil lubricated condition. Experimental results show that the wear amount of laser clad samples was quite small. The higher the content of amorphous structure, the smaller the wear amount. All friction coefficients of the clad samples versus grey iron pairs tended to stability and they were less than 0.1 after the sliding distance exceeded 2 km..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 953 (2000)
Trapezoid Slit of Slotted Oil Pipe by Laser Cutting
[in Chinese], and [in Chinese]
The characteristics of trapezoid slit of slotted oil pipe are summarized in this paper. The difficulty of laser cutting, the special equipment preparation and the processing methods are introduced. The result shows that quality of laser cutting is improved.The characteristics of trapezoid slit of slotted oil pipe are summarized in this paper. The difficulty of laser cutting, the special equipment preparation and the processing methods are introduced. The result shows that quality of laser cutting is improved..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 958 (2000)
Laser Physics
Nd:hosted Lasers Passive by Q-switched and Mode-locked by Saturable Absorbers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Nd:hosted lasers passively Q-switched or/and mode-locked by the plastics dye sheet, the LiF:F-2 colour centre crystal, the Cr4+:YAG crystal and the schott colour filter glass were investigated. A detail analysis of the mode-locking effect in combination with Q-switching was provided. Interpretations were given based onNd:hosted lasers passively Q-switched or/and mode-locked by the plastics dye sheet, the LiF:F-2 colour centre crystal, the Cr4+:YAG crystal and the schott colour filter glass were investigated. A detail analysis of the mode-locking effect in combination with Q-switching was provided. Interpretations were given based on the characteristic features of the materials, like saturation intensity and relaxation time..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 865 (2000)
Study of Diode-laser-pumped Cr3+:LiSrAlF6 Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this article, an all-solid-state laser, CW diode laser longitudinally pumped 1 mm thickness Cr3+:LiSrAlF6 crystal microchip laser is reported. 5.2 mW laser output was obtained in the parallel planar cavity. The laser spectral range of free oscillation was from 832 nm to 845 nm, and the slope efficiency was 15%.In this article, an all-solid-state laser, CW diode laser longitudinally pumped 1 mm thickness Cr3+:LiSrAlF6 crystal microchip laser is reported. 5.2 mW laser output was obtained in the parallel planar cavity. The laser spectral range of free oscillation was from 832 nm to 845 nm, and the slope efficiency was 15%..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 870 (2000)
Noise Character of SOA Directly Coupled with Fiber
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The noise character of strained MQW semiconductor optical amplifier has been studied in the paper. 7.7 dB noise figure of SOA directly coupled with fiber in both ends at 130 mA bias current shows that the noise character of SOA is improved by strained quantum well structure. Theoretical study explains experimental resuThe noise character of strained MQW semiconductor optical amplifier has been studied in the paper. 7.7 dB noise figure of SOA directly coupled with fiber in both ends at 130 mA bias current shows that the noise character of SOA is improved by strained quantum well structure. Theoretical study explains experimental result and shows that the noise figure of SOA can be further improved by reducing residual reflectivity..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 873 (2000)
Study on Focusing Spot Characteristic by Off-axis Parabolic Mirror
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on combining geometrical and physical optics, the effects of the angular misalignment of the optical axis and divergence angle on the focal power density are analyzed. Ray tracing analysis proves that a pair of focal lines are produced due to the angular misalignment, and diffractive optics proves that incident bBased on combining geometrical and physical optics, the effects of the angular misalignment of the optical axis and divergence angle on the focal power density are analyzed. Ray tracing analysis proves that a pair of focal lines are produced due to the angular misalignment, and diffractive optics proves that incident beam of Gaussian mode brings about reflective beam of near elliptical Gaussian mode. So that, the focal power density is decreased due to the angular misalignment. The parabolic mirror is very sensitive to misalignment, and the misalignment angle of the order of mrad magnitude is enough to decrease peak power density down to the half. The tolerance of the misalignment angle goes rapidly down with the incident beam diameter increasing. When the incident angle has a divergence angle, coma is produced to decrease the power density at focal plane..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 880 (2000)
Polarization Feature of A Relaxation Oscillation Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Using vectorial laser equation, the polarization feature of a relaxation oscillation laser is numerically analyzed. The numerical results reveal that the light field in the relaxation oscillation process is linearly polarized and the polarization direction varies with time. The single transverse-mode neodymium-doped fiUsing vectorial laser equation, the polarization feature of a relaxation oscillation laser is numerically analyzed. The numerical results reveal that the light field in the relaxation oscillation process is linearly polarized and the polarization direction varies with time. The single transverse-mode neodymium-doped fiber laser shows this feature..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 887 (2000)
Laser Raman Scattering Spectrum of Heroin
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, the practical measured X-ray diffraction, Fourier infrared absorption and laser Raman scattering spectra of heroin have been given. From the X-ray diffraction spectrum, it is found that the heroin belongs to the orthorhombic crystal system, and the basic vectors of the primitive cell are a=8.003, b=14.37In this paper, the practical measured X-ray diffraction, Fourier infrared absorption and laser Raman scattering spectra of heroin have been given. From the X-ray diffraction spectrum, it is found that the heroin belongs to the orthorhombic crystal system, and the basic vectors of the primitive cell are a=8.003, b=14.373, c=16.092×10-10 m. Based on the infrared absorption spectrum, the fundamental phonon energies of heroin are calculated: LO=0.0486, TO1=0.0555, TO2=0.0616, LA=0.0257, TA1=0.0097, TA2=0.0134 eV. Not only all of the Fourier infrared absorption peaks of the heroin consist of these elementary phonon energies in different combinations, but also every Raman backward scattering shift peaks of heroin consist of these elementary phonon energies in different combinations..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 891 (2000)
Spectroscopy
Study of Small Angle X-ray-diffraction Theory of Multilayer for Water Window Reign X-ray
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Because the period of reflector for water window X-ray reign is very small, it is difficult to get a continue surfaces of the absorption and spacing layers. This paper presents a simple physical model of change of mass density for calculating the diffraction intensity of multilayer, which is proved by the experiments oBecause the period of reflector for water window X-ray reign is very small, it is difficult to get a continue surfaces of the absorption and spacing layers. This paper presents a simple physical model of change of mass density for calculating the diffraction intensity of multilayer, which is proved by the experiments of the small angle X-ray diffraction. The theoretical analysis and experimental results show that the density distribution multilayer can produce a first strong diffraction intensity which is about 70%～80% difffraction intensity of that with sharp interface..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 10, 927 (2000)
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