Contents
1998
Volume: 18 Issue 1
24 Article(s)
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Atmospheric Optics and Oceanic Optics
Numerical Simulation of An Adaptive Optics System by Means of Modal Wavefront Reconstruction
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A theoretical model of numerical simulation of an adaptive optics (AO) system by modal wavefront reconstruction (i.e. by means of the Zernike polynomials expansion) is presented and the corresponding computer program is compiled. The AO computer program is combined with our simulation computational program of atmospherA theoretical model of numerical simulation of an adaptive optics (AO) system by modal wavefront reconstruction (i.e. by means of the Zernike polynomials expansion) is presented and the corresponding computer program is compiled. The AO computer program is combined with our simulation computational program of atmospheric propagation of laser beam to carry out a lot of simulation computations. It is found for the first time that there is an optimum term number of Zernike polynomials expansion. When the term number of Zernike polynomials expansion is higher than a certain value, results become worse very quickly. Zernike polynomials expansions of vertical arrangement and declined arrangement can give quite similar results. 15 terms of Zernike polynomials expansion which is thought usable in the wavefront reconstruction in literature, in fact can not give a correct result. The optimum term number gets lower as transverse wind speed is larger and the results of AO phase compensation by means of the model wavefront reconstruction with optmium term number are slightly better than those by means of the direct wavefront gradient control method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 103 (1998)
Diffraction and Gratings
An Optical Design of 3-D Diffraction Grating in Soft X-Ray Spectra Based on Scalar Theory
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An asymptotic formalism used in the scalar domain is derived for studying the behavior of three-dimension diffraction gratings used in small groove pitch and near normal incidence for soft X-ray. The theory is applied to study 3-D lamellar gratings and results in a preliminary design.An asymptotic formalism used in the scalar domain is derived for studying the behavior of three-dimension diffraction gratings used in small groove pitch and near normal incidence for soft X-ray. The theory is applied to study 3-D lamellar gratings and results in a preliminary design..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 99 (1998)
Fourier Optics and Signal Processing
Gray Image Recognition Based on Vector Quantization and Hopfield Network Model
[in Chinese], [in Chinese], and [in Chinese]
A new kind of gray-level image recognition method is presented. By the image segmentation based on the vector quantization, the gray-level image can be mapped into an Hopfield network, each neuron has several states. The performance of this model is compared with that of the traditionary model. It is concluded that theA new kind of gray-level image recognition method is presented. By the image segmentation based on the vector quantization, the gray-level image can be mapped into an Hopfield network, each neuron has several states. The performance of this model is compared with that of the traditionary model. It is concluded that the new one not only has a smaller number of neurons and interconnections, but also has better error correction capabilities..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 112 (1998)
Instrumentation, Measurement and Metrology
Fringe-Pattern Connection Method for Shape Measurementof 3-D Large Objects
[in Chinese], [in Chinese], and [in Chinese]
The techniques for shape measurement of 3-D object have widely been applied. Both moire topography and modified lighting technique have many advantages such as non-contact, high accuracy and high speed. But they inevitably meet with some difficulties, such as shadow noise and low contrast for measuring large object. CoThe techniques for shape measurement of 3-D object have widely been applied. Both moire topography and modified lighting technique have many advantages such as non-contact, high accuracy and high speed. But they inevitably meet with some difficulties, such as shadow noise and low contrast for measuring large object. Considering the correlation between two patterns sampled from the same object, a frigne-pattern connection method based on MAOST is proposed which can be effectively used to measure 3-D shape of large objects without all difficulties happened in conventional techniques. Mathematical mode, computer simulation and experimental results are presented..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 74 (1998)
Optical Superresolution through the Combination of Confocal Scanning Microscopy and Apodization
[in Chinese], [in Chinese], and [in Chinese]
The application of an appropriate apodization film to an ordinary lens makes the point amplitude response asymptotic to a Dirac-delta function, or causes an arbitrarily narrow depth of focus. This implicates that we may achieve lateral or axial superresolution through implementing an apodization film. However, the largThe application of an appropriate apodization film to an ordinary lens makes the point amplitude response asymptotic to a Dirac-delta function, or causes an arbitrarily narrow depth of focus. This implicates that we may achieve lateral or axial superresolution through implementing an apodization film. However, the large sidelobes spreading all through the field, which are produced by imposing an apodization film onto an ordinary lens, may result in a noisy background degrading the image contrast. In this paper, we put forward a scheme of implementing a confocal setup to suppress the large sidelobes. Furthermore, a configuration for achieving three-dimensional suoerresolution is depicted and discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 80 (1998)
Automatic Profilometry by Dual-Frequency of Optical Fiber Projection Grating
[in Chinese], [in Chinese], and [in Chinese]
A novel automatic profilometry technique by dual-frequency of optical fiber projection grating is introduced. A one to two (1×2) optical fiber coupler is utilized to generate sinusoidal intensity projection grating. A piezoelectric (PZT) cylinder wrapped by one arm of the optical fiber coupler is utilized to introA novel automatic profilometry technique by dual-frequency of optical fiber projection grating is introduced. A one to two (1×2) optical fiber coupler is utilized to generate sinusoidal intensity projection grating. A piezoelectric (PZT) cylinder wrapped by one arm of the optical fiber coupler is utilized to introduce phase shift. Different frequencies of projection gratings can be got easily through adjusting the separate distance of the two projecting optical fiber ends. Three-dimension shape can be measured automatically with this technique even in the cases of true discontinuities and noise in the phase..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 86 (1998)
Measuring Scratch Width by Sampling Diffracted-Light Intensity: Experiment
[in Chinese], [in Chinese], and [in Chinese]
An experimental arrangement has been built for measuring scratch width by sampling diffracted-light intensity. Using this arrangement, several specimen are measured, and the scratches widths can be obtained efficiently and quickly. In general case, the measuring error is smaller than ±15%.An experimental arrangement has been built for measuring scratch width by sampling diffracted-light intensity. Using this arrangement, several specimen are measured, and the scratches widths can be obtained efficiently and quickly. In general case, the measuring error is smaller than ±15%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 90 (1998)
Temperature Field Reconstruction by Carrier Electronic Speckle Pattern Interferometry and Computerized Tomography
[in Chinese], and [in Chinese]
Three dimensional temperature field reconstruction has been carried out by using carrier electronic speckle pattern interferometry (CESPI) and computerized tomography. The characteristics of this technique are discussed.Three dimensional temperature field reconstruction has been carried out by using carrier electronic speckle pattern interferometry (CESPI) and computerized tomography. The characteristics of this technique are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 95 (1998)
Lasers and Laser Optics
Effect of Finite Bandwidths of Light Fields on Inversionless Light Amplification and Refractive Index
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The conditions of the maximum refractive index with vanishing absorption and the effect of the finite bandidths of the probe and driving field on the index of refraction and the gain are analyzed based on a Raman driven four level system. The calculated results show that the maximum index of refraction with vanishing aThe conditions of the maximum refractive index with vanishing absorption and the effect of the finite bandidths of the probe and driving field on the index of refraction and the gain are analyzed based on a Raman driven four level system. The calculated results show that the maximum index of refraction with vanishing absorption can be achieved by changing the detuning between the frewuency of the driving field and the resonant atomic transition or by changing the intensity of the driving field. The finite bandwidths of the driving and the probe field decrease the gain and change the value of the index of refraction, especially of the driving field..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 1 (1998)
Study on “Green Problem” of LD Pumped Intracavity-Doubled Nd: YVO4/KTP Green Lasers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The green noise of Nd: YVO 4/KTP intracavity doubled green lasers vs cavity length and pump power has been measured. The key factors influencing the green output stability at multilongitudinal modes have been found through theoretical analysis. The calculated result in good agreement with the experiments.The green noise of Nd: YVO 4/KTP intracavity doubled green lasers vs cavity length and pump power has been measured. The key factors influencing the green output stability at multilongitudinal modes have been found through theoretical analysis. The calculated result in good agreement with the experiments..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 9 (1998)
Generation of 5 GHz 16.2 ps Ultrashort Optical Pulse
[in Chinese], [in Chinese], and [in Chinese]
The elimination of chirp by combining F-P spectral window and normal dispersion fiber was theoretically and experimentally studied. The ultrashort optical pulse with chirp parameter smaller than the critical value, the repetitive rate of 5 GHz and pulse width of 16.2 ps was experimentally generated. The soliton transmiThe elimination of chirp by combining F-P spectral window and normal dispersion fiber was theoretically and experimentally studied. The ultrashort optical pulse with chirp parameter smaller than the critical value, the repetitive rate of 5 GHz and pulse width of 16.2 ps was experimentally generated. The soliton transmission was achieved after the chirp of the optical pulse was eliminated, and the high-order soliton with pulse width of 13 ps was observed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 14 (1998)
Materials
Photonic Band Structure of Simple Cubic Lattice in Chiral Medium——Plane Wave Method
[in Chinese], [in Chinese], and [in Chinese]
The plane wave method is developed for calculating photonic band structure in chiral medium, at this basis, the photonic band structure of simple cubic lattice made of chiral medium is calculated. Results show that cutoff frequencies below which there are no propagating modes appear in both of two kinds scc lattices whThe plane wave method is developed for calculating photonic band structure in chiral medium, at this basis, the photonic band structure of simple cubic lattice made of chiral medium is calculated. Results show that cutoff frequencies below which there are no propagating modes appear in both of two kinds scc lattices which are the array of “chiral spherical atoms” in dielectric material and the array of “dielectric spherical atoms” in chiral matrix. There is a cutoff grequency below which there are no propagating modes. The potential application of the photonic lattice is discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 118 (1998)
Measurement of Cr4+:YAG Saturable Absorption
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The saturable absorption in Cr～4+: YAG was measured. The ground and excited-state absorption cross sections of σgs=11×10-19 cm2, σes=1.2×10-19 cm2 were obtained by experiments and different model calculations for different samples.The saturable absorption in Cr～4+: YAG was measured. The ground and excited-state absorption cross sections of σgs=11×10-19 cm2, σes=1.2×10-19 cm2 were obtained by experiments and different model calculations for different samples..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 124 (1998)
Nonlinear Optics
Experiment on Thermal Dark Spatial Optical Solitons in Chlorophyll Acetone
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The experimental setup and the even boundary condition of the thermal dark spatial optical solitons was designed, and the experiment was realized in chlorophyll acetone. Numerical results of thermal dark solitons were simulated by the split step Fourier method, and the results were agreement with the experiment.The experimental setup and the even boundary condition of the thermal dark spatial optical solitons was designed, and the experiment was realized in chlorophyll acetone. Numerical results of thermal dark solitons were simulated by the split step Fourier method, and the results were agreement with the experiment..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 37 (1998)
Optical Devices
Measurement and Analysis of Diffraction Efficiency of Fresnel Microlens Arrays
[in Chinese], [in Chinese], and [in Chinese]
The various definitions of diffraction efficiency of binary microlens arrays are sumd up according to the practical measurement method in the reported papers, and the suggestionsd for the standard definition and the corresponding measurement method are presented. The measurement system of diffraction efficiency suggestThe various definitions of diffraction efficiency of binary microlens arrays are sumd up according to the practical measurement method in the reported papers, and the suggestionsd for the standard definition and the corresponding measurement method are presented. The measurement system of diffraction efficiency suggested in this paper is easy to operate and can be used to measure the diffraction efficiency of the Fresnel microlens arrays..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 41 (1998)
Theoretical Analysis of the Characterization of Mach-Zehnder Wavelength Division Multiplexer using Fiber Grating
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Transfer matrix method is used to study the characterization of Mach-Zehnder (M-Z) wave division multiplexer (WDM) using fiber Bragg grating. The influence of relative structure parameter on device characterization is analyzed, and optimum structure parameter is obtained.Transfer matrix method is used to study the characterization of Mach-Zehnder (M-Z) wave division multiplexer (WDM) using fiber Bragg grating. The influence of relative structure parameter on device characterization is analyzed, and optimum structure parameter is obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 49 (1998)
Optical Modulators Using Semicondutor Waveguide in Fiber Ring Lasers
[in Chinese], [in Chinese], and [in Chinese]
Optical modulators using semiconductor waveguide in fiber ring lasers are investigated theoretically. The analysis shows that the modulation mechanism resulted from the polarization control in the fiber loop and polarization adjustment of semiconductor waveguide. This provides a theoretical evidence for a new type of sOptical modulators using semiconductor waveguide in fiber ring lasers are investigated theoretically. The analysis shows that the modulation mechanism resulted from the polarization control in the fiber loop and polarization adjustment of semiconductor waveguide. This provides a theoretical evidence for a new type of self-staring mode-locked and self-Q-switched meachanism in fiber lasers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 56 (1998)
Effect of Focusing Error and Illumination with Polychromatic Light on Zone Plate Light Spot
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The property of light spot of zone plate in misfocusing conditions is considered. The effect of band width of illuminating light is discussed. Relative intensity distribution, radius of light spot and total energy in light spot have been calculated numericaly. Allowable limit of the largest focusing error of the zone pThe property of light spot of zone plate in misfocusing conditions is considered. The effect of band width of illuminating light is discussed. Relative intensity distribution, radius of light spot and total energy in light spot have been calculated numericaly. Allowable limit of the largest focusing error of the zone plate which will be used in the soft-X-ray scanning microscope has been calculated. The limit of resolution of the soft X-ray scanning microscope has been shown..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 62 (1998)
Preparation of Blue Display Materials and Devices
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
SrS phosphors doped with Ce～3+ was prepared by reducing SrSO_4 in H_2 and CS_2 atmosphere, and the influence of these two methods on the structure of powder and the characteristic of photoluminescence was studied. The maximum brightness of Ce: SrS TFEL was 950 cd/m2 under 1000 Hz. The powder of SrGa2S4 doped with CeSrS phosphors doped with Ce～3+ was prepared by reducing SrSO_4 in H_2 and CS_2 atmosphere, and the influence of these two methods on the structure of powder and the characteristic of photoluminescence was studied. The maximum brightness of Ce: SrS TFEL was 950 cd/m2 under 1000 Hz. The powder of SrGa2S4 doped with Ce3+ was made by high-temprature solid solution method. The Ce: SrGa2S4 thin film was prepared by RF sputtering and the crystal characteristic of it was improved by annealing in H2S atmosphere at over 600℃, also the characteristic was developed. SrGa2S4 thin film electroluminescent device with ceramic as substrate and insulator had a little electoluminescence..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 68 (1998)
Spectroscopy
Spatially Modulated Imaging Interferometry
[in Chinese], [in Chinese], and [in Chinese]
The spatially modulated imaging interferometry (SMII) is introduced. A double dihedral corner spatially modulated imaging interferometer based on a monolithic Michelson interferometer (SMIIM) is presented. The general model of super throughput interferometer, the basic design equations and the tolerance of the main errThe spatially modulated imaging interferometry (SMII) is introduced. A double dihedral corner spatially modulated imaging interferometer based on a monolithic Michelson interferometer (SMIIM) is presented. The general model of super throughput interferometer, the basic design equations and the tolerance of the main errors of SMIIM are discussed.
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 18 (1998)
Resonant Two-Photon Ionization Spectra of External Vibrations of the van der Waals Complex p C6H4FCH3…Ar
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Resonant two photon ionization spectrum of p C_6H_4FCH_3...Ar through the S 1←S 0 transition revealed a number of bands near the origin 0 0 band, and all these bands except for thoes due to the internal rotational transitions of the CH 3 group are assigned to the low frequency external vibrations. Quantum calculations Resonant two photon ionization spectrum of p C_6H_4FCH_3...Ar through the S 1←S 0 transition revealed a number of bands near the origin 0 0 band, and all these bands except for thoes due to the internal rotational transitions of the CH 3 group are assigned to the low frequency external vibrations. Quantum calculations using the method of linear combination of three dimensional harmonic osillator products were carried out to assist the spectral assignments..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 23 (1998)
Multiphoton Ionization Process Study of Ethylamine via Mass Spectrometry
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The multiphoton ionization mass spectrum of ethylamine in the 440-484 nm region is studied. The MPI process follows the molecular ion fragmentation pattern. Most of the molecular ions fragment by β-cleavage after they have been formed from (2+2) resonance-enhanced multiphoton ionization through 3s Rydberg state. The frThe multiphoton ionization mass spectrum of ethylamine in the 440-484 nm region is studied. The MPI process follows the molecular ion fragmentation pattern. Most of the molecular ions fragment by β-cleavage after they have been formed from (2+2) resonance-enhanced multiphoton ionization through 3s Rydberg state. The fragment ion CH2=N+H2 is most abundant. A part of molecule ions absorb one photon, then the C-H(CH2) bond cleavage gives CH3CH=N+H2 ions. The easiest fragmentation pathway of CH2=N+H2 and CH3CH=N+H2 is the loss of H2 molecule, procucing CH=N+H and C2H4N+ ions respectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 28 (1998)
Spectroscopic Ellipsometry and the Sense of Elliptical Polarization
[in Chinese], and [in Chinese]
Spectroscopic ellipsometry is a useful technique for studying surfaces and thin films. It has been used to determine the real part and imaginary part of indices and thicknesses of thin layer synchronically. However, photometric ellipsometer can only measure cos Δ, cannot determine directly the value of Δ at each waveleSpectroscopic ellipsometry is a useful technique for studying surfaces and thin films. It has been used to determine the real part and imaginary part of indices and thicknesses of thin layer synchronically. However, photometric ellipsometer can only measure cos Δ, cannot determine directly the value of Δ at each wavelength. We apply the Kramers-Kronig transformation relation to complex reflection ratio and derive Ψ-Δ relation. As an example, we approach a single layer film on a substrate..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 33 (1998)
Thin Films
Normal-Incidence Mo/B4C Soft X-Ray Multilayer
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The preliminary results of making Mo/B4C multilayer mirrors at wavelength below 10.0 nm are presented. The multilayer structure was calculated at designed wavelength (λ=8.0 nm), and the sample mirror were deposited by magnetron sputtering technique.The preliminary results of making Mo/B4C multilayer mirrors at wavelength below 10.0 nm are presented. The multilayer structure was calculated at designed wavelength (λ=8.0 nm), and the sample mirror were deposited by magnetron sputtering technique..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 1, 109 (1998)
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