Journals >Chinese Journal of Lasers
Contents
1999
Volume: 26 Issue 8
19 Article(s)
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Research Article
Experimental Study of a Low-debris Laser-produced PlasmaSoft-X-ray Source
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A low-debris CO2 target soft-X-ray source and a home-made transmission grating spectrometer are described in this paper, the preliminary experimental results of spectral emission and debris measurement of the source are given.A low-debris CO2 target soft-X-ray source and a home-made transmission grating spectrometer are described in this paper, the preliminary experimental results of spectral emission and debris measurement of the source are given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 687 (1999)
A System for Arbitrary Shaping of Q-switch Laser Pulses Using KTP Pockels Cell and Microstrip Transmission Lines
[in Chinese], and [in Chinese]
A Pockels cell utilizing the effective EO coefficient γc1 of the relatively new EO crystal KTP is fabricated. Its thermo-optic properties were studied experimentally, and compensation of the static birefringence of the switch was achieved by temperature turning. Then the device was successfully used to slice and shape A Pockels cell utilizing the effective EO coefficient γc1 of the relatively new EO crystal KTP is fabricated. Its thermo-optic properties were studied experimentally, and compensation of the static birefringence of the switch was achieved by temperature turning. Then the device was successfully used to slice and shape the 50 ns single axial mode, Nd:YLF Q-switched laser pulses. The experiments demonstrated that the KTP Pockels cell required a low half-wave voltage and had small capacitance. When driven by a pair of microstrip transmission lines, 1～10 ns pulses with almost arbitrarily tunable shapes could be obtained, and the Pockels cell was not only the simple pulse-slicing device (as usually believed before) any more. A thermally and dispersion compensated KTP Pockels cell is also discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 691 (1999)
Improvement to Dispersion Property of a Linearly Chirped Grating by Optimizing the Distribution of Coupling Coefficient
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper the reflctivity peak value and bandwidth of a linearly chirped grating are calculated. A second order moment of the dispersion is defined. A quality factor is used to exactly describe the dispersion property of the grating. With this quality factor, the grating structure is optimized by selecting differenIn this paper the reflctivity peak value and bandwidth of a linearly chirped grating are calculated. A second order moment of the dispersion is defined. A quality factor is used to exactly describe the dispersion property of the grating. With this quality factor, the grating structure is optimized by selecting different coupling lengths and the distribution of coupling coefficient to improve its dispersion property. The results show that the method reported in this paper is a quantitative one being able to optimize the structure of gratings efficiently..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 696 (1999)
Singal Estimate and Statistical Error Analysis for Edge Technique
[in Chinese]
The signal estimate and statistical error analysis for edge technique is made in details in this paper. The function and the value of an error factor are given in ideal and actual conditions. The effects of signal averaging and background noise on the statistical errors are discussed. The final conclusion is: edge techThe signal estimate and statistical error analysis for edge technique is made in details in this paper. The function and the value of an error factor are given in ideal and actual conditions. The effects of signal averaging and background noise on the statistical errors are discussed. The final conclusion is: edge technique has high signal-to-noise ratio, small statistical errors, large measuring range in high accuracy, and can prevent back ground noise in some way..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 701 (1999)
Study of Surface Topographic Measurement by a Mirau Correlation Microscope
[in Chinese], [in Chinese], and [in Chinese]
A surface profile system based on a Mirau interferometer is described which uses the correlation method. This method may overcome the difficulty encountered in a PSMI profiler, in which the vertical response is limited by the diffraction effect of the objective. The system gives the accurate vertical scale of the measuA surface profile system based on a Mirau interferometer is described which uses the correlation method. This method may overcome the difficulty encountered in a PSMI profiler, in which the vertical response is limited by the diffraction effect of the objective. The system gives the accurate vertical scale of the measured surface..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 706 (1999)
Holography and Information Processing
Distortion-invariant Optical Pattern Recognition Based on the Fuzzy Logic
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, multi-value hit-or-miss transformation (MVHMT) is introduced into a joint transform correlator (JTC) for binary image recognition. Considering fuzzy concepts are lost MVHMT improves the ability of the ordinary morphological hit-or-miss transformation (HMT) because it reduces the decision effect of the piIn this paper, multi-value hit-or-miss transformation (MVHMT) is introduced into a joint transform correlator (JTC) for binary image recognition. Considering fuzzy concepts are lost MVHMT improves the ability of the ordinary morphological hit-or-miss transformation (HMT) because it reduces the decision effect of the pixels that is easily disturbed by rotation and scalling distortion. Not only MVHMT can realize the precision recognition between two images because no information of the input images is lost, but also it has a better distortion-invariant ability for scaling and rotation than the ordinary HMT. Using a novel multi-value complementary encoding method, MVHMT is performed on a JTC in one step. With a high-level thresholding value, the correct justification can be achieved from the correlated resultant image. The simulation results are given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 721 (1999)
An Ultrashort Laser-pulse Electronic Holography System Suitable for Imaging Through Highly Scattering Media
[in Chinese], [in Chinese], and [in Chinese]
The principle of electronic holography using ultrashort laser-pulse for imaging through highly scattering media is discussed. An electronic holography system is established which is suitable for imaging through highly scattering media. This system consists of a CCD camera, an imaging processor and is programmed for numThe principle of electronic holography using ultrashort laser-pulse for imaging through highly scattering media is discussed. An electronic holography system is established which is suitable for imaging through highly scattering media. This system consists of a CCD camera, an imaging processor and is programmed for numerical reconstructing and image processing. The experiments show that this system is feasible. The advantages of this system are also discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 729 (1999)
Study of the Same-source Crosstalk of the Optical Cross-connection in WDM All Optical Networks
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, the impact of crosstalk on the optical cross-connection of the WDM all optical networks is analyzed. The results show that in the dynamic OXC, there exits a kind of same-wavelength crosstalk, the same-source crosstalk. Its impact is more severe than that of other kinds of crosstalks. A new OXC structure In this paper, the impact of crosstalk on the optical cross-connection of the WDM all optical networks is analyzed. The results show that in the dynamic OXC, there exits a kind of same-wavelength crosstalk, the same-source crosstalk. Its impact is more severe than that of other kinds of crosstalks. A new OXC structure to minimize its negative effect is proposed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 734 (1999)
Laser Manufacturing
Polymer Surface Treatment by XeCl Excimer Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A polymer surface treatment irradiated system by a XeCl excimer laser is designed. The hydrophilic character of fluorocarbon-resin with water is improved by solutions such as H2O, H3BO3(1%), and NaOH(0.5%) reacting with fluorocarbon-resin while the XeCl excimer laser is irradiating. The relationship between the contactA polymer surface treatment irradiated system by a XeCl excimer laser is designed. The hydrophilic character of fluorocarbon-resin with water is improved by solutions such as H2O, H3BO3(1%), and NaOH(0.5%) reacting with fluorocarbon-resin while the XeCl excimer laser is irradiating. The relationship between the contact angle of water on the surface of polymer and the laser intensity and laser pulse shots is measured. The smallest contact angle of 28° is obtained. The mechanism of these phenomena is discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 745 (1999)
Half-polarity Correlation Method for Laser Speed Measurement
[in Chinese], [in Chinese], and [in Chinese]
This paper puts forward a new method for laser speed measurement with half-polarity correlation. It not only has the advantage that the digital signal is easy to delay on polarity correlation, but also keeps the advantage that no amplitude message is lost on the classical correlation method. In this paper, it is provedThis paper puts forward a new method for laser speed measurement with half-polarity correlation. It not only has the advantage that the digital signal is easy to delay on polarity correlation, but also keeps the advantage that no amplitude message is lost on the classical correlation method. In this paper, it is proved that the half-polarities correlation method can give the same maximum amplitude as the classical correlation method. A preliminary test result is presented..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 749 (1999)
Restraining Role of Dynamics Metamorphic Materials to the Cold Crack of Hardened Layers Obtained by Selective Laser Sintering
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Proceeded from the point of view to alter the crystallization state, the effect of excitation plasticization by use of dynamics metamorphic materials containning silicon or containning zircornium etc. for the wear resistant alloy layer obtained by selective laser sintering is studied in this paper. The influence of theProceeded from the point of view to alter the crystallization state, the effect of excitation plasticization by use of dynamics metamorphic materials containning silicon or containning zircornium etc. for the wear resistant alloy layer obtained by selective laser sintering is studied in this paper. The influence of the metamophic materials on the sintering layer′s chemical composition and on the crystalline state is discussed. The result thows that the structure of the sintering layer can be thinned down and the phenomenon of brittlely cracking in the sintering layer may be eliminated by use of appropriate dynamics metamophic materials..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 755 (1999)
Research on the Influence of Posterior Capsular Fold on Eye′s Imaging Property
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, on the basis of a study of the morbidity mechanism of posterior capsular fold (PCF) after the artificial intraocular lens implantation, we have researched into the cause of the influence of PCF on eye′s imaging property in numerical quantities according to the theory of imaging optics.In this paper, on the basis of a study of the morbidity mechanism of posterior capsular fold (PCF) after the artificial intraocular lens implantation, we have researched into the cause of the influence of PCF on eye′s imaging property in numerical quantities according to the theory of imaging optics..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 759 (1999)
Laser Physics
Computational Simulation of the Single-segment Nd:glass Glass Amplifier
[in Chinese], [in Chinese], and [in Chinese]
A computational simulation of the single-segment Nd:glass amplifier(SSA) has been made. By introducing the temporal factor, in our numerical codes the parameters of the discharge net can be optimized, and some important laser parameters, such as the storage efficiency and stored energy etc., can be calculated out from A computational simulation of the single-segment Nd:glass amplifier(SSA) has been made. By introducing the temporal factor, in our numerical codes the parameters of the discharge net can be optimized, and some important laser parameters, such as the storage efficiency and stored energy etc., can be calculated out from the given stored energy of electric capacitors. The codes have been checked up in the use of the experimental data at LLNL, showing the ability of predicted performance..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 673 (1999)
Laser-diode-pumped Cr4+:YAG Repetitively Q-switched Nd3+:YAG Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, a laser-diode-pumped Cr4+:YAG repetitively Q-switched Nd3+:YAG laser is studied theoretically and experimentally. The analytical expression of the pulse repetition rate including the effect of gain medium field splittings and finite lower level lifetime is derived. The pulse energies, pulse widths and reIn this paper, a laser-diode-pumped Cr4+:YAG repetitively Q-switched Nd3+:YAG laser is studied theoretically and experimentally. The analytical expression of the pulse repetition rate including the effect of gain medium field splittings and finite lower level lifetime is derived. The pulse energies, pulse widths and repetition rates in different conditions are measured and the experimental results show rough agreement with the theoretical predictions..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 678 (1999)
Research of Properties of an Internal Optical Parametric Oscillator (IOPO)and Optical Parametric Amplifier (IOPA)
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In the cavity of a repetition rate Q-switched YAG laser, the stable internal optical parametric oscillator (IOPO) and the internal parametric amplifier (IOPA) are realized. The main results are as follows: the threshold of IOPO is smaller than 20 mJ, the maximum output energy is 35.9 mJ, the corresponding conversion efIn the cavity of a repetition rate Q-switched YAG laser, the stable internal optical parametric oscillator (IOPO) and the internal parametric amplifier (IOPA) are realized. The main results are as follows: the threshold of IOPO is smaller than 20 mJ, the maximum output energy is 35.9 mJ, the corresponding conversion efficient is 45%, and the peak output wavelength is 1570 nm. The solid-state instrument is compact and easy to miniaturize..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 683 (1999)
Numerical Research on the Self-focusing of Optical Beams
[in Chinese], [in Chinese], and [in Chinese]
The vector theory on self-focusing of a high-power laser beam in the nonlinear isotropic medium is presented. Based on the laser beam tracking algorithm with self-adapting, which is the modification of the split-step Fourier methods, the numerical results show that the peak intensity on the axis of the light beam reducThe vector theory on self-focusing of a high-power laser beam in the nonlinear isotropic medium is presented. Based on the laser beam tracking algorithm with self-adapting, which is the modification of the split-step Fourier methods, the numerical results show that the peak intensity on the axis of the light beam reduces little by little, and it takes on some space periods. The non-collapse of light beam in self-focusing is given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 711 (1999)
Electrooptic Pockels Effect of a C60 LB Monolayer
[in Chinese], and [in Chinese]
The second order nonlinearity of C60 was deduced from the Pockels response of a mixed C60/AA LB monolayer by using electrooptically modulated attenuated total reflection spectroscopy. The obtained considerable second order susceptibility of C60 χ(2)(-ω;ω,0)=0.5×10-12 m/V(i.e. 1.3×10-9 esu), in agreement with The second order nonlinearity of C60 was deduced from the Pockels response of a mixed C60/AA LB monolayer by using electrooptically modulated attenuated total reflection spectroscopy. The obtained considerable second order susceptibility of C60 χ(2)(-ω;ω,0)=0.5×10-12 m/V(i.e. 1.3×10-9 esu), in agreement with that obtained from the SHG measurement. And, the superpolarizability of C60, β=1.1×10-30 esu, was calculated using a monolayer model..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 717 (1999)
Materials and Thin Films
The Influence of Concentration of Yb3+ Ions on Luminescence and Fluorescence Lifetime in Fluorozirconate and Phosphate Glasses
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Absorption spectra, emission spectra and fluorescence lifetime were measured with different concentrations of Yb3+-doped, the emission cross section σe of Yb3+ was calculated. Dependence of luminescence intensity and fluorescence lifetime on concentration of Yb3+ was analyzed. No remarkable influence of concentration oAbsorption spectra, emission spectra and fluorescence lifetime were measured with different concentrations of Yb3+-doped, the emission cross section σe of Yb3+ was calculated. Dependence of luminescence intensity and fluorescence lifetime on concentration of Yb3+ was analyzed. No remarkable influence of concentration of Yb3+ ions on luminescence intensity and fluorescence lifetime was observed in the case of low level Yb3+ doped. Concentration quenching occurred when high level Yb3+ was doped. Luminescence intensity and fluorescence decreased because of it. The mechanism of concentration quenching was discussed and explained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 739 (1999)
Study of the Technology of Small Spot Scanning for Laser Conditioning of Optical Coatings at 532 nm
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A significant limitation to the operating fluence (or peak power) of high-peak-power lasers is the laser induced damage threshold (LIDT) of optical components and optical coatings. A lot of work has been done to improve the LIDT of optical coatings in the past years, and recently, it is discovered that laser conditioniA significant limitation to the operating fluence (or peak power) of high-peak-power lasers is the laser induced damage threshold (LIDT) of optical components and optical coatings. A lot of work has been done to improve the LIDT of optical coatings in the past years, and recently, it is discovered that laser conditioning is a new technology to enhance laser resistance of the optical coatings. In this paper the latest experimental result from this group of laser conditioning of optical coatings at 532 nm is reported. The method utilized is the small laser spot scanning and the step by step energy raising. Coating samples, which were prepared with various deposition techniques, were conditioned. The effect of enhance of the laser resistance was shown in the great majority of the samples. The feasibility and effectiveness of the laser conditioning were confirmed. The possible mechanism of the laser conditioning was explained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 8, 763 (1999)
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