Contents
1999
Volume: 19 Issue 1
25 Article(s)
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Atmospheric Optics and Oceanic Optics
The Parallel Algorithms of Wavefront Computing in Adaptive Optics
[in Chinese], [in Chinese], and [in Chinese]
In adaptive optics system, wavefront computation refers to a class of processing consisting of wavefront slope computation, wavefront reconstruction and wavefront control algorithm. We studied the realization of the optimization mapping of the wavefront computing algorithm from the representive layer to the architecturIn adaptive optics system, wavefront computation refers to a class of processing consisting of wavefront slope computation, wavefront reconstruction and wavefront control algorithm. We studied the realization of the optimization mapping of the wavefront computing algorithm from the representive layer to the architecture layer. Two SIMD-based parallel algorithms, the doubling algorithm and the partitioning algorithm are proposed according to the existing parallel computing theory. On the basis above, the MAC cycle and I/O cycle are used to scale the performance of the two algorithms. Their computing efficiencies on the SIMD array processor are analyzed and compared in detail..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 72 (1999)
Probability Distribution of Laser Irradiance Scintillation in a Real Turbulent Atmosphere
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A probability distribution model for the light log-intensity fluctuation in turbulent atmosphere was introduced by taking consideration of the skewness and the kurtosis. The model is suitable for fitting the probability distrbution from experimental data. It was found experimentally that under the weak fluctuation condA probability distribution model for the light log-intensity fluctuation in turbulent atmosphere was introduced by taking consideration of the skewness and the kurtosis. The model is suitable for fitting the probability distrbution from experimental data. It was found experimentally that under the weak fluctuation condition the probability distribution is close to a normal distrbution when the turbulence is well deveploped, otherwise the ditribution will deviate from the normal distribution and the skewness of the log-intensity probability distribution is alwsys negative and the kurtosis positive..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 81 (1999)
Fiber Optics and Optical Communications
Transfer Function Analysis of Diffused Planar Optical Waveguides
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new numerical method-transfer function method-for analysis and calculation of optical waveguides is presented. By using this method, the characteristics of propagation for diffused planar waveguides are calculated and compared with the finite element method. The results show that it is a relatively simple and exact mA new numerical method-transfer function method-for analysis and calculation of optical waveguides is presented. By using this method, the characteristics of propagation for diffused planar waveguides are calculated and compared with the finite element method. The results show that it is a relatively simple and exact method for using transfer function method to deal with the optical waveguides with graded refractive index profile..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 50 (1999)
TE Waves in Multiple Quantum Well Waveguides with Nonlinear Cladding
[in Chinese]
Formulas and method of calculation are presented for analysis of optical nonlinearity and bistability of TE modes in a multiple quantum well waveguide with nonlinear cladding. It is demonstrated that in the thin film approximation, the method of root-mean-square equivalent index for the waveguide core is an accurate, eFormulas and method of calculation are presented for analysis of optical nonlinearity and bistability of TE modes in a multiple quantum well waveguide with nonlinear cladding. It is demonstrated that in the thin film approximation, the method of root-mean-square equivalent index for the waveguide core is an accurate, efficient and time saving method for characteristics analysis. Dependence of modal refractive index on total waveguide power, bistability between core power and total power, dependence of field profile on modal index are analysed and the influence of waveguide parameters on them are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 57 (1999)
Theory of Magnetostatic Wave Propagation and Magnetooptic Bragg Diffraction in YIG-GGG Waveguide Under Nonuniform Bias Magnetic Field
[in Chinese], and [in Chinese]
A theoretical treatment on the propagation characteristics of magnetostatic forward volume wave (MSFVW), in a four-layer YIG-GGG (Yttrium iron garnet-Gadolinium gallium garnet) waveguide structure under a nonuniform bias magnetic field, and related guided-wave magnetooptic (MO) Bragg diffraction is presented. A nonunifA theoretical treatment on the propagation characteristics of magnetostatic forward volume wave (MSFVW), in a four-layer YIG-GGG (Yttrium iron garnet-Gadolinium gallium garnet) waveguide structure under a nonuniform bias magnetic field, and related guided-wave magnetooptic (MO) Bragg diffraction is presented. A nonuniform bias magnetic field of appropriate profile along the propagation path is found to have the effects of enhancing the power density of MSFVW and thus the corresponding MO Bragg diffraction efficiency, and to have the possibility of controlling the degree of divergence in the diffracted light..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 63 (1999)
Fourier Optics and Signal Processing
Reverse Geometry Based Direct Volume Reconstruction
[in Chinese], [in Chinese], and [in Chinese]
A novel direct volume reconstruction method based on reverse geometry for cone beam X-ray projections is presented. We combine the cone beam boundary reconstruction with reverse geometry by extending one or two detectors to many point-shaped detectors located purposively in 3D space. The boundary reconstruction algoritA novel direct volume reconstruction method based on reverse geometry for cone beam X-ray projections is presented. We combine the cone beam boundary reconstruction with reverse geometry by extending one or two detectors to many point-shaped detectors located purposively in 3D space. The boundary reconstruction algorithm and its numerical simulation on two volume phantoms have shown that the new reverse geometry is worth considering and exploiting compared to the conventional X-ray cone beam boundary reconstruction in case of X-ray projection noise..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 35 (1999)
Study on Accurate Phase-Demodulating of Phase-Approaching of Projected Grating Used in 3D Detection
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The problems are analysed in practical 3D detection by phase approaching of projected grating that frequency-moving in frequency domain and the correspondence between measured surface and reference plane have great effect on the accuracy of phase-demodulating. An appropriate method for avoiding frequency-moving and a nThe problems are analysed in practical 3D detection by phase approaching of projected grating that frequency-moving in frequency domain and the correspondence between measured surface and reference plane have great effect on the accuracy of phase-demodulating. An appropriate method for avoiding frequency-moving and a new concept of full-field reference plane are proposed. Their perfect perfomance has been verified..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 41 (1999)
Research on the Interferogram Processing
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A series of image processing methods of fringe analysis is given. It includes mean processing of intensity distribution using the anti-Gauss distribution, edge detection instead of binary method and an effective thinning method. The practical methods have been used to process the interferogram of optical computer tomogA series of image processing methods of fringe analysis is given. It includes mean processing of intensity distribution using the anti-Gauss distribution, edge detection instead of binary method and an effective thinning method. The practical methods have been used to process the interferogram of optical computer tomography and good results are obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 45 (1999)
Lasers and Laser Optics
Diode End-Pumped Additive Pulse Mode Locked Nd:YLF Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A diode-end-pumped Nd:YLF laser with self-starting additive pulse mode-locking is investigated, The mechanics of the pulse shortening and the condition of the self-starting are analized. When pumped with the maximum power of 2.4 W, stable CW mode locked trains of 2 ps pulses are generated at 1.053 μm, with an average eA diode-end-pumped Nd:YLF laser with self-starting additive pulse mode-locking is investigated, The mechanics of the pulse shortening and the condition of the self-starting are analized. When pumped with the maximum power of 2.4 W, stable CW mode locked trains of 2 ps pulses are generated at 1.053 μm, with an average effective output power of 76 mW, corresponding to a peak power of 283 W..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 23 (1999)
Investigation on Time-and Space-Evolution of the Resonance Double Lines of Aluminium in Laser Induced Plasma
[in Chinese], [in Chinese], and [in Chinese]
Based the time-and space-resolved spectroscopy and the measurements of intensity of resonant double-lines 396.15 nm and 394.40 nm from laser induced plasma, the time- and space-evolution characteristics of resonance double lines of aluminium in a plasma were obtained and mechanism was discussed. Air was used as surrounBased the time-and space-resolved spectroscopy and the measurements of intensity of resonant double-lines 396.15 nm and 394.40 nm from laser induced plasma, the time- and space-evolution characteristics of resonance double lines of aluminium in a plasma were obtained and mechanism was discussed. Air was used as surrounding atmospheres. The pressure was set up to 101 kPa..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 28 (1999)
Materials
Spectrum and Structure of Eu3+:Y2SiO5 Crystal
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Narrow line fluorescence spectra of Eu3+:Y2SiO5 crystal are obtained by exciting with Ar+ laser at 514.5 nm, 488 nm and He-Cd laser at 441.6 nm. Complex spectral structure is analyzed and identified, which is understood as originating from taking off the energy level degeneracy of Eu3+ in the host crystal field and theNarrow line fluorescence spectra of Eu3+:Y2SiO5 crystal are obtained by exciting with Ar+ laser at 514.5 nm, 488 nm and He-Cd laser at 441.6 nm. Complex spectral structure is analyzed and identified, which is understood as originating from taking off the energy level degeneracy of Eu3+ in the host crystal field and the possession of two inequivalent lattice sites of Eu3+ in the host crystal. X-ray powder diffraction pattern of Eu3+:Y2SiO5 shows that the the crystal is monoclinic. The lattice constants a, b, c and β are obtained by a simulation with the measured difraction angles, and found that the lattice constants a, b, c are slightly larger but very close to those of undoped Y2SiO5 crystal..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 127 (1999)
Spectroscopy and Laser Performance of Yb3+ Doped YAG Crystal
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Spectral performances of Yb:YAG crystal were studied. The optimal Yb3+ doping level in Yb:YAG crystal is 10at%, which is determined by the fluorescence lifetime measurement. It is shown that the cooperative up-conversion processes of Yb3+→Tm3+ energy transfer is responsible for the fluorescence quenching at high Yb3+ dSpectral performances of Yb:YAG crystal were studied. The optimal Yb3+ doping level in Yb:YAG crystal is 10at%, which is determined by the fluorescence lifetime measurement. It is shown that the cooperative up-conversion processes of Yb3+→Tm3+ energy transfer is responsible for the fluorescence quenching at high Yb3+ doping level. 300 mW of pulsed laser output power at 1030 nm was obtained by means of InGaAs LD pumped 20at% Yb:YAG crystal thin chip..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 132 (1999)
Crystal-Field Spectra of Cr, Ca:YAG Crystal
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
High quality optical crystal of Cr, Ca:YAG was grown by Czochralski method and annealed in an oxidization atmosphere successfully in our laboratory. VIS-NIR absorption spectra, crystal-field parameters and characteristics of Cr4+ centres in the crystal, which are influenced by divalent compensation Ca2+ ion, are determHigh quality optical crystal of Cr, Ca:YAG was grown by Czochralski method and annealed in an oxidization atmosphere successfully in our laboratory. VIS-NIR absorption spectra, crystal-field parameters and characteristics of Cr4+ centres in the crystal, which are influenced by divalent compensation Ca2+ ion, are determined and analyzed in detail. Some evidences suggest that a reasonable doping concentration would be favourable to emitting tunable laser from such a laser crystal..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 136 (1999)
Nonlinear Optics
Analysis of Induced Self-Pumping Phase Conjugation and Optical Bistability in a Photorefractive Crystal (BaSr)TiO3
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A theoretical explanation of induced self-pumping phase conjugation (ISPPC) is presented. The bistability and reversibility and irreversibility of ISPPC in given conditions are obtained by numerical calculation of the corresponding coupled-wave equation. The calculated results show qualitative agreement with the experiA theoretical explanation of induced self-pumping phase conjugation (ISPPC) is presented. The bistability and reversibility and irreversibility of ISPPC in given conditions are obtained by numerical calculation of the corresponding coupled-wave equation. The calculated results show qualitative agreement with the experimental results obtained previously..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 18 (1999)
Optical Devices
Optimization of a Practical Birefringence Fiber-Optic Temperature Sensor
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on the birefringence effect, a practical reflective fiber-optic temperature sensor was developed with the polarization-modulated method. The relations among the accuracy, sensitivity and parameters including the source, crystal and optical fiber, are analyzed in terms of theory and experiments. The methods of selBased on the birefringence effect, a practical reflective fiber-optic temperature sensor was developed with the polarization-modulated method. The relations among the accuracy, sensitivity and parameters including the source, crystal and optical fiber, are analyzed in terms of theory and experiments. The methods of selecting the optimal system parameters are illustrated..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 87 (1999)
Dynamic Characteristics of a Mach-Zehnder Wavelength Converter
[in Chinese], [in Chinese], and [in Chinese]
By using the high frequency saturation filtering effect and dynamic carrier recovery time, the dependence of the frequency chirping and intersymbol interference (ISI) of a wavelength converter based on cross-phase modulation in Mach-Zehnder wavelength converter is analyzed. While the extinction ratio is kept the same aBy using the high frequency saturation filtering effect and dynamic carrier recovery time, the dependence of the frequency chirping and intersymbol interference (ISI) of a wavelength converter based on cross-phase modulation in Mach-Zehnder wavelength converter is analyzed. While the extinction ratio is kept the same at different probe power for out-phase converting, the poorer performance of the converted signal is due to a longer gain recovery time and the larger intersymbol interference. But for in-phase converting, the high probe or fast carrier recovery time is not surely better than that of low probe power..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 93 (1999)
Temperature Measurement Accuracy of the Distributed Optical Fiber Raman Photons Temperature Sensor System
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In the distributed optical fiber Raman photons temperature senser (DOFRPTS) system, spontaneous Raman photons are carriers of temperature signal. On the 2 km optical fiber, 1000 points have been sampled on time used for the measurement of temperature field in space. The position of measurement point was determined by RIn the distributed optical fiber Raman photons temperature senser (DOFRPTS) system, spontaneous Raman photons are carriers of temperature signal. On the 2 km optical fiber, 1000 points have been sampled on time used for the measurement of temperature field in space. The position of measurement point was determined by Raman scattering optical time domain reflection (OTDR) technique. Signal and noise of the system have been discussed, the measured temperature accuracy of the DOFRPS system is ±1℃ determined by S/N ratio..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 100 (1999)
Rigorous Diffraction Analysis for Small Periods Binary Optical System
[in Chinese], [in Chinese], and [in Chinese]
A rigorous vector grating analysis approach-BKK approach, which can be used to analyze the big caliber and big view binary optical system, is introduced. This method is applied to calculate the diffraction efficiencies accurately for arbitrary grating profiles, incident angles, substrate indexes and wavelengths in the A rigorous vector grating analysis approach-BKK approach, which can be used to analyze the big caliber and big view binary optical system, is introduced. This method is applied to calculate the diffraction efficiencies accurately for arbitrary grating profiles, incident angles, substrate indexes and wavelengths in the same order of grating period. The diffraction efficiencies are given and compared with scalar results..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 106 (1999)
Acceptable Error of Etching Depth in Ion Beam Etching Microlens
[in Chinese], [in Chinese], and [in Chinese]
Based on the diffraction optical principle, a formula of the diffraction efficiency and etching depth error of the microlens is obtained. The results show that the time control method of ion beam etching meets the needs of micro-fabrication of L=1′s microlens and the etching depth error should be smaller than 87 nm in Based on the diffraction optical principle, a formula of the diffraction efficiency and etching depth error of the microlens is obtained. The results show that the time control method of ion beam etching meets the needs of micro-fabrication of L=1′s microlens and the etching depth error should be smaller than 87 nm in the micro-fabrication of L>1′s microlens..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 113 (1999)
Monochromator Beamline Design at 4～120 nm Spectral Range
[in Chinese], [in Chinese], and [in Chinese]
A new plane grating monochromator is used in the surface-physics beamline at the Hefei National Synchrotron Radiation Lab. (NSRL) as its light-dispersing instrument. Its optical imaging system consists of a plane grating and a spherical mirror. The wavelength tuning is performed by rotating the pre-spherical mirror aroA new plane grating monochromator is used in the surface-physics beamline at the Hefei National Synchrotron Radiation Lab. (NSRL) as its light-dispersing instrument. Its optical imaging system consists of a plane grating and a spherical mirror. The wavelength tuning is performed by rotating the pre-spherical mirror around an axis outside of the surface while rotating the grating around its center. The monochromator offers high optical transmission and high spectral resolving power at 4～120 nm wavelength range..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 117 (1999)
A New Type Fresnel Phase Waveband Plate
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By utilizing the properties of liquid crystal molecular alignment controllable by electric field as well as its optical anisotropy, a new type Fresnel phase waveband plate has been designed. This device has the advantages of easy fabrification, low cost and resistance to scratch.By utilizing the properties of liquid crystal molecular alignment controllable by electric field as well as its optical anisotropy, a new type Fresnel phase waveband plate has been designed. This device has the advantages of easy fabrification, low cost and resistance to scratch..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 124 (1999)
Quantum Optics
Effects of Correlated Noises on Dynamic Properties of a Single-Mode Laser
[in Chinese], [in Chinese], and [in Chinese]
The expressions for correlation functions, power spectrum and correlation time of the intensity of a single-mode laser driven by two white noises with a exponential function correlation form were calculated by linear approximation method. According to the calculated results, the effects of correlation strength and corrThe expressions for correlation functions, power spectrum and correlation time of the intensity of a single-mode laser driven by two white noises with a exponential function correlation form were calculated by linear approximation method. According to the calculated results, the effects of correlation strength and correlation time between noises on the above quantities are discussed, and are compared with the situation of a delta function correlation form between moises..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 7 (1999)
Quantum Logical Gate by Laser Coherent Excitation
[in Chinese], and [in Chinese]
A new scheme is proposed to realize the Fredkin quantum logic gate by using laser-controlled excitation of state in the three-mode laser and three-level system, in which the population depends on the laser phases and amplitudes.A new scheme is proposed to realize the Fredkin quantum logic gate by using laser-controlled excitation of state in the three-mode laser and three-level system, in which the population depends on the laser phases and amplitudes..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 13 (1999)
Rapid Communications
Intracavity Frequency Doubling Effects in Different Picosecond Unstable Resonators with KTP Crystal
[in Chinese], and [in Chinese]
By using KTP crystal as intracavity frequency doubling generator of a mode-locked Nd:YAP laser, efficient SHG in colliding pulse mode-locked (CPM) unstable resonator with antiresonant ring (ARR) and confocal unstable resonator has been demonstrated. The energy conversion efficiencies are 53.4% and 60.2%, pulse durationBy using KTP crystal as intracavity frequency doubling generator of a mode-locked Nd:YAP laser, efficient SHG in colliding pulse mode-locked (CPM) unstable resonator with antiresonant ring (ARR) and confocal unstable resonator has been demonstrated. The energy conversion efficiencies are 53.4% and 60.2%, pulse durations in fundamental wave are 8 ps and 18 ps, and the maximum energy fluctuation in second harmonic wave are 10.6% and 12.5%, respectively. The characteristics in both resonators and their experimental results are theoretically analyzed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 141 (1999)
Spectroscopy
Hyperfine Zeeman Spectra of Cesium Atoms 62S1/2→52D5/2 Electric Quadrupole Transition
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Hyperfine Zeeman spectra of the cesium atoms 62S1/2→52D5/2 electric quadrupole transition is studied experimentally by the thermionic diode and photoionization technique, corresponding calculations for the energy structure and relative intensity of the transition are conducted. The experimental and theoretical results Hyperfine Zeeman spectra of the cesium atoms 62S1/2→52D5/2 electric quadrupole transition is studied experimentally by the thermionic diode and photoionization technique, corresponding calculations for the energy structure and relative intensity of the transition are conducted. The experimental and theoretical results are compared and discussed. The results of this study are significant to the efficient use of a high-resolution external field spectral method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 19, Issue 1, 1 (1999)
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