Contents
1998
Volume: 18 Issue 4
26 Article(s)
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Fourier Optics and Signal Processing
High Accuracy Computation of OTF
[in Chinese], and [in Chinese]
Directly from the theory of Kirchhoff diffraction, without any approximation about mathematical models, a series of improved digital calculation ways are used to ensure the high accuracy of OTF calculation. Through the comparative computation of several same type of softwares and typical lenses, the result shows that tDirectly from the theory of Kirchhoff diffraction, without any approximation about mathematical models, a series of improved digital calculation ways are used to ensure the high accuracy of OTF calculation. Through the comparative computation of several same type of softwares and typical lenses, the result shows that this software is suitable for the accurately setting the value of OTF standard lens, and also sutitable for the design and computation of verious large reltive apertures and wide angle optical systems..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 436 (1998)
Three-Dimensional Imaging of ICF Targets
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A CT technique applied to ICF is developed and a three dimensional (3D) image reconstruction propram (CT3D) is performed. The 3D images of target′s plasma are reconstructed by using a multiplicatic algebraic reconstruction technique (MART) from five pinhole camera images obatined along different sight directions. The tA CT technique applied to ICF is developed and a three dimensional (3D) image reconstruction propram (CT3D) is performed. The 3D images of target′s plasma are reconstructed by using a multiplicatic algebraic reconstruction technique (MART) from five pinhole camera images obatined along different sight directions. The technique has been used to measure the three dimensional distribution of X ray of laser plasma experiments in the “Xingguang Ⅱ” facility, and the good results are obtained. It show that the CT technique can be applied to ICF experiments..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 440 (1998)
Instrumentation, Measurement and Metrology
Surface Plasmon Spectroscopy for Measuring the Surface Roughness of Metallic Films
[in Chinese], and [in Chinese]
A method for determining the surface roughness parameters of metal film with surface plasmon spectroscopy is proposed. The angular distribution of scattering light intensity from two kinds of silver films, prism/silver film/air and prism/LB film/silver film/air was measured under the condition that surface plasmon was A method for determining the surface roughness parameters of metal film with surface plasmon spectroscopy is proposed. The angular distribution of scattering light intensity from two kinds of silver films, prism/silver film/air and prism/LB film/silver film/air was measured under the condition that surface plasmon was excited between the silver and air. By fitting the experiment data with calculating curves of theory, the characterization parameters for stochastic roughness interface were obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 474 (1998)
A Robust Subpixel Algorithm for the Center of Circle Detecting
[in Chinese], [in Chinese], and [in Chinese]
The part alignment is an important step for automated optical inspection of printed circuit board (PCB). Because conventional image recognition algorithm could only be implemented at pixel accuracy, it is not satisfied with the requirements of PCB inspection. Through the use of geometric symmetry of a circle, a robust The part alignment is an important step for automated optical inspection of printed circuit board (PCB). Because conventional image recognition algorithm could only be implemented at pixel accuracy, it is not satisfied with the requirements of PCB inspection. Through the use of geometric symmetry of a circle, a robust subpixel algorithm for the center of circle detecting is presented. By the proposed method the measurement error might be less than 0.01 pixel for noise free images. In the meantime, experiments show that the algorithm has a relatively small bias in the presence of noise..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 481 (1998)
Lasers and Laser Optics
KTP Optical Parametric Oscillator with Noncollinear Pump
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The phasematching condition in noncollinear pump OPO is analyzed. It indicates that round trip phasematching can be achieved if the OPO is in noncritical phasematching at collinear case. Using a KTP OPO, we got 31% of 1.06 μm pump be converted into 1.57 μm eye safe output at a noncollinearity of 1 degree.The phasematching condition in noncollinear pump OPO is analyzed. It indicates that round trip phasematching can be achieved if the OPO is in noncritical phasematching at collinear case. Using a KTP OPO, we got 31% of 1.06 μm pump be converted into 1.57 μm eye safe output at a noncollinearity of 1 degree..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 398 (1998)
Cavity Dispersion Nonaxiality of Self-Mode-Locked Solid State Lasers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The cavity dispersion nonaxiality (CDN) in a self mode locked solid state laser is calculated. It is shown that the transverse effect of CDN is not less than that of self focusing in most of the stability regions and seriously affects the generation and the compression of the self mode locking pulse. The experimental rThe cavity dispersion nonaxiality (CDN) in a self mode locked solid state laser is calculated. It is shown that the transverse effect of CDN is not less than that of self focusing in most of the stability regions and seriously affects the generation and the compression of the self mode locking pulse. The experimental results prove that the self mode locked regime of a Ti: sapphire laser without hard apertures is in the vicinity of the point where the cavity axes are coaxial in the gain medium..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 403 (1998)
Time Resolved Beam-Quality of Copper Vapor Laser with Injection Controlling
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The beam quality of an unstable resonator copper vapor laser with injection controlling has been studied experimently. Measurement results of the time resolved beam divergence shows that the injected signal accelerates the improvement course of unstable resonator output. Because of the exist of amplified spontaneous emThe beam quality of an unstable resonator copper vapor laser with injection controlling has been studied experimently. Measurement results of the time resolved beam divergence shows that the injected signal accelerates the improvement course of unstable resonator output. Because of the exist of amplified spontaneous emission, when the injected beam is near the diffraction limit, the pulse width of the injected laser and delay time must be appropriate for obtaining ideal output performance..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 408 (1998)
Phenomenon of Laser Wavefront Intermittently Distortion Induced by Adjustment of the Resonant Cavity Length
[in Chinese], and [in Chinese]
The phenomenon of laser wavefront intermittently distortion induced by periodically adjusting the resonent cavity length of a CO 2 laser was observed. It leads to the signal discontinuity of a coherent FM CW laser radar. The preliminary analyses indicate that this phenomenon is connected with the laser branch line. WheThe phenomenon of laser wavefront intermittently distortion induced by periodically adjusting the resonent cavity length of a CO 2 laser was observed. It leads to the signal discontinuity of a coherent FM CW laser radar. The preliminary analyses indicate that this phenomenon is connected with the laser branch line. When this distortion occurs, the laser branch line doesn′t shift and the microscopic characteristics of the transverse mode have no change..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 412 (1998)
Relativistic Collisional Absorptionin High-Intense-Laser-Driven Plasmas
[in Chinese], [in Chinese], and [in Chinese]
The collisional heating rate of a fully ionized plasma driven by a strong electromagnetic pump wave is re examined analytically under the condition of P≥10 18 W/cm 2. The high frequency conductivity model of Dawson and Oberman is extended into the case in which the quiver velocity is so large that the relativistic effeThe collisional heating rate of a fully ionized plasma driven by a strong electromagnetic pump wave is re examined analytically under the condition of P≥10 18 W/cm 2. The high frequency conductivity model of Dawson and Oberman is extended into the case in which the quiver velocity is so large that the relativistic effect must be considered..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 421 (1998)
Experimental Study of X-Ray Emission from the Rear Side of Gold Foil
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Temporal and spectral behaviors of X ray radiation emitted from the rear side of laser irradiated gold foil, and transmitted laser energy have been investigated experimentally. An X ray source with high X ray flux and low transmitted laser energy could be obtained in laboratory.Temporal and spectral behaviors of X ray radiation emitted from the rear side of laser irradiated gold foil, and transmitted laser energy have been investigated experimentally. An X ray source with high X ray flux and low transmitted laser energy could be obtained in laboratory..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 426 (1998)
Population Trapping in Laser Isotopes Separation
[in Chinese], [in Chinese], and [in Chinese]
A process of four photon three step resonant ionization is investigated in terms of dressed atom model, and a kind of population trapping is found which is independent to the ionizing rate. Numerical calculation with time dependent Schrodinger equation shows that the population trapping can be removed by suitably deA process of four photon three step resonant ionization is investigated in terms of dressed atom model, and a kind of population trapping is found which is independent to the ionizing rate. Numerical calculation with time dependent Schrodinger equation shows that the population trapping can be removed by suitably detuning the laser frequency from the corresponding Bohr frequency..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 431 (1998)
Materials
Growth and Defects of LiGaO2Crystal Used for GaN Epitaxy
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The lattice mismatch between LiGaO 2 and GaN is only 0.2%, so LiGaO 2 is expected to be a promising substrate for the epitaxy of GaN. In present work, large LiGaO 2 single crystal (φ15×60 mm) with high quality has been grown using Czochralski method . The crystalline quality was characterized by means of chemicalThe lattice mismatch between LiGaO 2 and GaN is only 0.2%, so LiGaO 2 is expected to be a promising substrate for the epitaxy of GaN. In present work, large LiGaO 2 single crystal (φ15×60 mm) with high quality has been grown using Czochralski method . The crystalline quality was characterized by means of chemical etching, optical microscope and TEM. The influences of growth parameters on LiGaO 2 crystal quality were invetigated. The growth rate along 〈100〉 is the most rapid, that along 〈001〉 is lowest. γ Ga 2O 3 inclusions tend to emerge in LiGaO 2 crystal owing to the volatilization of Li 2O, therefore, a lot of dislocations were induced, which form the subgrain boundary parallel to (001) plane. High quality LiGaO 2 crystal can be obtained by using the charge with excess Li 2O and adopting appropriate growth parameters..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 499 (1998)
Sensitization Effect of Ce3+to Er3+in YAG Crystal
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The sensitive effect of cerium to erbium ions has been analyzed by solving the rate quations of level transition in Ce, Er: YAG and Er: YAG crystals. It is shown that this effect increases the laser intensity at wavelengths both 1.66 and 2.94 μm, but only changes the relation between the population inversion of 4I 13/2The sensitive effect of cerium to erbium ions has been analyzed by solving the rate quations of level transition in Ce, Er: YAG and Er: YAG crystals. It is shown that this effect increases the laser intensity at wavelengths both 1.66 and 2.94 μm, but only changes the relation between the population inversion of 4I 13/2 and 4I 15/2 levels and the concentration of Er 3+ ions..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 503 (1998)
Nonlinear Optics
The Length of Waveguide in Raman Beam Cleanup System
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The waveguide length in Raman beam cleanup system is calculated, considering various facts such as the pump depletion, gain dispersion and crossed beam geometry, and the pump distortion. The results, compared with experimental data, predict that the optimal length of waveguide must be the least among various limitationThe waveguide length in Raman beam cleanup system is calculated, considering various facts such as the pump depletion, gain dispersion and crossed beam geometry, and the pump distortion. The results, compared with experimental data, predict that the optimal length of waveguide must be the least among various limitation. The analysis of results is presented..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 416 (1998)
Optical Devices
Study on Single-Grating Strecher in Chirped-Pulse Amplification
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A single grating pulse strecher in chired pulse amplification is demonstrated. To explain its pricinple of streching, we get a formula of dispersion and streching factor. Through the numerical analysis, the relationship between the streching factor and its related parameters, and the change of temporal duration of laseA single grating pulse strecher in chired pulse amplification is demonstrated. To explain its pricinple of streching, we get a formula of dispersion and streching factor. Through the numerical analysis, the relationship between the streching factor and its related parameters, and the change of temporal duration of laser pulses streched by pulse strecher are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 457 (1998)
Experimental Study of a New Azo Polymer Film for Real Time Holography with High Diffraction Efficiency
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new azopolymer material has been developed. Real time holograms were recorded at 633 nm, and read out by beam with the same wavelength. High diffraction efficiency above 10% was obtained, and large photo induced birefringence δ n>10 -3 was measured.A new azopolymer material has been developed. Real time holograms were recorded at 633 nm, and read out by beam with the same wavelength. High diffraction efficiency above 10% was obtained, and large photo induced birefringence δ n>10 -3 was measured..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 462 (1998)
Theory About Coupled Wave Equations of Acousto-Electro-Optic Effect
[in Chinese], [in Chinese], and [in Chinese]
The coupled wave equations of acousto optic (AO) effect and electro optic (EO) effect are united into coupled wave equations of acousto electro optic (AEO) effect. A formula about diffraction efficiency is given by the equations.The coupled wave equations of acousto optic (AO) effect and electro optic (EO) effect are united into coupled wave equations of acousto electro optic (AEO) effect. A formula about diffraction efficiency is given by the equations..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 466 (1998)
Fabrication of Intergrated GeSi/Si Superlattic PIN Photodetector with Waveguide
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The GeSi/Si superlattices structure is grown on the n +/n - Si wafer by MBE method. The detector and the Si rib waveguides are formed by reactive ion etching. The integration of Si waveguide and GeSi/Si superlattices PIN photodetector is fabricated throuth the suitable process. The minimum dark current of PIN detector The GeSi/Si superlattices structure is grown on the n +/n - Si wafer by MBE method. The detector and the Si rib waveguides are formed by reactive ion etching. The integration of Si waveguide and GeSi/Si superlattices PIN photodetector is fabricated throuth the suitable process. The minimum dark current of PIN detector is 0.8 μA and the maximum photocurrent is 2.7 μA at 5 V reverse bias. The maximum overall quantum efficiency of photodetector of 14.2% was obtained. The working wavelenth λ=1.3 μm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 471 (1998)
Physical Optics
Soliton Transmission Based on the Chain of Different Dispersion Fiber
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Soliton transmission based on the chain of different dispersion fiber was numerically and experimentally studied. The results showed that the different assembly of different dispersion fiber had different result. There was a reasonable assembly when fibers had different dispersion. Even if it was the same fiber chain, Soliton transmission based on the chain of different dispersion fiber was numerically and experimentally studied. The results showed that the different assembly of different dispersion fiber had different result. There was a reasonable assembly when fibers had different dispersion. Even if it was the same fiber chain, it would need different energy and have differnt stability to achievesoliton transmission if the direction of the input fiber was exchanged with the direction of output fiber..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 446 (1998)
Atmospheric-Turbulence-Degraded Light Intensity Images: Size Measurement and Description of Deformation Characteristic
[in Chinese], [in Chinese], and [in Chinese]
Basing on the space distribution characteristics of the long term light image in the turbulent atmosphere the background signal of a CCD imaging system can be determined accurately, and then we can measure the image size accuratly with the CCD imaging system. The maximal radius and space filling ratio related to engineBasing on the space distribution characteristics of the long term light image in the turbulent atmosphere the background signal of a CCD imaging system can be determined accurately, and then we can measure the image size accuratly with the CCD imaging system. The maximal radius and space filling ratio related to engineering applications are introduced for the description of the deformation characteristics of the light image degraded in the turbulent atmosphere by analyzing both simulation data and experimental data. Finally we mentioned the phenomenon of the enhancement of light intensity in certain regions in the simulated images and its potential importance..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 451 (1998)
Quantum Optics
Preparation of Schrodinger Cat States by Conditional Measurements in the Two-Photon Jaynes-Cumming Model
[in Chinese], and [in Chinese]
We have proven that the Schrodinger cat states can be generated by conditional measurement on the atom in the Jaynes Cumming model with a Kerr like medium. The special states such as even coherent states, odd coherent state and Yurke Stoler coherent state may be aqcuired by further choosing some suitable parameters, suWe have proven that the Schrodinger cat states can be generated by conditional measurement on the atom in the Jaynes Cumming model with a Kerr like medium. The special states such as even coherent states, odd coherent state and Yurke Stoler coherent state may be aqcuired by further choosing some suitable parameters, such as the time of measurement, initial state of the atom, and Kerr nonlinear constant. The sub poisson distribution can be revealed under the high field approximation (n>>1) only in the existence of Kerr medium..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 385 (1998)
The Influence of Noise on Two-Mode Competition Effects
[in Chinese], [in Chinese], and [in Chinese]
The influence of noise on two mode competition is discussed. Using linear stability analysis, some significant results are obtained.The influence of noise on two mode competition is discussed. Using linear stability analysis, some significant results are obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 391 (1998)
Rapid Communications
Er3+Doped Fiber Laser with All Fiber Dispersive Cavity
Some experimental results on Er 3+ doped fiber laser pumped by a 971 nm semiconductor laser are reported. A fiber laser with all fiber dispersive cavity formed by a fiber loop reflector and a fiber grating is proposed and successfully demonstrated. Laser output with linewidth narrower than 0.05 nm at 1.55 μm waveband iSome experimental results on Er 3+ doped fiber laser pumped by a 971 nm semiconductor laser are reported. A fiber laser with all fiber dispersive cavity formed by a fiber loop reflector and a fiber grating is proposed and successfully demonstrated. Laser output with linewidth narrower than 0.05 nm at 1.55 μm waveband is obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 507 (1998)
Relation between Dispersion and Reflective Response in Gratings and Its Application
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The electronic and magnetic field in a grating is a Hamiltonian system. Its conserved quantities are used to get the relation between the dispersion and the reflective coefficient. This is helpful for the analysis of spectral characteristics of the gratings.The electronic and magnetic field in a grating is a Hamiltonian system. Its conserved quantities are used to get the relation between the dispersion and the reflective coefficient. This is helpful for the analysis of spectral characteristics of the gratings..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 510 (1998)
Thin Films
Measurement and Calculation of Anisotropic Polymer Film Parameters
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The one side leaky wave technique is discussed for determination of the refractive indices n o , n e and thickness d of the anisotropic polymer thin film through the measurement of the coupling angles corresponding to leaky modes, and the calculation of their effective indices and solving the corresponding mode equatioThe one side leaky wave technique is discussed for determination of the refractive indices n o , n e and thickness d of the anisotropic polymer thin film through the measurement of the coupling angles corresponding to leaky modes, and the calculation of their effective indices and solving the corresponding mode equations. The results of measurement and calculation for PT PEK c film are: n o =1.6525±0.0014, n e = 1.6439 ±0.0019, d=2.33±0.32 μm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 486 (1998)
Photosensitive Defects in Germania Doped Silica Glasses
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The nature of photosensitive defects in germania doped silica glasses under irradiation of 488 nm Argon laser and 193 nm ArF excimer laser are investigated. From the careful measurement of UV induced absorption bands, photoluminescence changes, and electron spin resonance (ESR) experiments, we found that the 5.1 eV gerThe nature of photosensitive defects in germania doped silica glasses under irradiation of 488 nm Argon laser and 193 nm ArF excimer laser are investigated. From the careful measurement of UV induced absorption bands, photoluminescence changes, and electron spin resonance (ESR) experiments, we found that the 5.1 eV germania defect absorption band in fibers is composed of 5.06 eV photo bleachable band and 5.17 eV relative photochemically stable band. And the photoluminescence at 295 nm corresponding to 5.06 eV defects is decaying with 5.06 eV photobleaching. While the luminescence at 395 nm is attributed to 5.17 eV defect and its intensity keeps constant with UV irradiation. The structural models of two defects are presented, the bleaching dynamic of absorption with laser irradiation is analyzed, and the photosensitive processes with different laser sources are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 4, 491 (1998)
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