Contents
1998
Volume: 18 Issue 10
39 Article(s)
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Atmospheric Optics and Oceanic Optics
Compensation Effect of an Adaptive Optics System for Atmosphere Induced Wavefront Perturbation I. Theoretical Anaysis
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The structure function of residual wavefront phase perturbation compensated by an adaptive optics system has been derived by means of frozen turbulence hypothesis and geometric optics approach. According to the relationship between Strehl ratio of the system and the residual phase structure function, the analytical expThe structure function of residual wavefront phase perturbation compensated by an adaptive optics system has been derived by means of frozen turbulence hypothesis and geometric optics approach. According to the relationship between Strehl ratio of the system and the residual phase structure function, the analytical expression about the influence of spatial temporal transfer function, atmospheric turbulence, transverse wind speed along the light propagation path, angular velocity of the observed object and time delay of the system on the compensation effect of the system has been obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1366 (1998)
Compensation Effect of an Adaptive Optics System for Atmosphere Induced Wavefront Perturbation II. Analysis of the Result for Light Propagation in Horizontal Atmosphere
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The condition of light propagating in the horizontal atmosphere has been considered. It is shown that the compensation effect of an adaptive optics system is strongly related with transverse wind along the light propagation path. When intensity of the atmospheric turbulence becomes stronger, or the cut off spatial freqThe condition of light propagating in the horizontal atmosphere has been considered. It is shown that the compensation effect of an adaptive optics system is strongly related with transverse wind along the light propagation path. When intensity of the atmospheric turbulence becomes stronger, or the cut off spatial frequency of the adaptive optics system becomes higher, the influence of transverse wind becomes stronger. It is also shown that the influence of transverse wind on the compensation effect for the atmospheric turbulence induced wavefront perturbaton on spherical wave is stronger than that on plane wave..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1372 (1998)
Fiber Optics and Optical Communications
Study on Fiber Directional Coupler with Fiber Bragg Gratings in Its Arms
[in Chinese], [in Chinese], and [in Chinese]
A general model for fiber directional coupler with fiber Bragg gratings in its arms is presented. The output expression of any arm is obtained when input is from an arm. As examples, two types of F P interferometer are analyzed. We find that an exchange equivalence relationship exists between them. For the first time wA general model for fiber directional coupler with fiber Bragg gratings in its arms is presented. The output expression of any arm is obtained when input is from an arm. As examples, two types of F P interferometer are analyzed. We find that an exchange equivalence relationship exists between them. For the first time we descrie the concepts of amplitude modulation caused by in fiber Bragg gratings in F-P resonator..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1380 (1998)
[in Chinese]
[in Chinese]
Analytical solutions of electromagnetic fields in the elliptical core chiral optical fiber have been studied. The modal fields distribution and modal characteristic equations are obtained. The numerical solutions for the modal characteristic equations of the even and odd fundamental mode are given. For different aspectAnalytical solutions of electromagnetic fields in the elliptical core chiral optical fiber have been studied. The modal fields distribution and modal characteristic equations are obtained. The numerical solutions for the modal characteristic equations of the even and odd fundamental mode are given. For different aspect ratios of the elliptical core, effects of chirality parameter on the characteristics such as dispersion curves, birefringence and modal dispersion of the fundamental modes in the elliptical core chiral optical fiber are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1385 (1998)
Holography
Reconfiguration of Topplogy in an Opto-Electronic Neural System
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An efficient method of programmable reconfiguration of the topology in an optical/digital neural system with large scale is proposed. The principle and application technique of the method are described. And the experimental results of operation of a single layer feedback network as well as a multi layer feedforward netAn efficient method of programmable reconfiguration of the topology in an optical/digital neural system with large scale is proposed. The principle and application technique of the method are described. And the experimental results of operation of a single layer feedback network as well as a multi layer feedforward network in a NP1024 optical/digital neuroprocessor by using the proposed method are reported..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1306 (1998)
Optical Pattern Recognition Based on Hybrid Interpattern Associative Neural Network
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By combining autoassociation and heteroassociation, an optical pattern recognition (OPR) system based on hybrid interpattern associative neural network is proposed. In this neural network, the input vector not only addresses itself by autoassociation but also addresses its mated vector by heteroassociation, so the corrBy combining autoassociation and heteroassociation, an optical pattern recognition (OPR) system based on hybrid interpattern associative neural network is proposed. In this neural network, the input vector not only addresses itself by autoassociation but also addresses its mated vector by heteroassociation, so the correct addressing probability is increased. Compared with the matched spatial filter OPR system, the addressing results are direct, and this scheme is feasible and promising..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1311 (1998)
Optical Hit-Miss Transformation for Image Processing Based on Incoherent Single-Channel Correlation
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A simple algorithm of morphological hit miss transform by single channel correlation in an incoherent optical correlator is proposed, which is based on Boolean decomposition for morphological function and thresholding operation for correlation. In reported optical hit miss processor, an original input image correlates A simple algorithm of morphological hit miss transform by single channel correlation in an incoherent optical correlator is proposed, which is based on Boolean decomposition for morphological function and thresholding operation for correlation. In reported optical hit miss processor, an original input image correlates with both foreground and background structuring element pair. By properly coding the foreground and background structuring element pair, and then thresholding at the number of foreground SE level, the single channel correlation for hit miss transform can be realised. Thus, The hit miss transform can be realised optically in one parallel step. Any morphological image processing functions can be implemented by repeated use of the optical processor with different structuring elements. Experimental results are given..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1317 (1998)
Optical Single-Block Modified Gamma Network Using Layered Thermally Fixed Photorefractive Holograms
[in Chinese], [in Chinese], and [in Chinese]
A scheme of using CO 2 laser beams to thermally fix layers of photorefractive phase holograms in a single block of LiNbO 3 crystal to fabricate a solid state miniaturized optical system is suggested. Theoretical analysis shows that by the heating with two face to face narrow beams a layer like temperature distribution A scheme of using CO 2 laser beams to thermally fix layers of photorefractive phase holograms in a single block of LiNbO 3 crystal to fabricate a solid state miniaturized optical system is suggested. Theoretical analysis shows that by the heating with two face to face narrow beams a layer like temperature distribution switable for fixing can be reached. In a primary experiment, a stage of the Gamma network is realized in a single blook of photorefractive LiNbO 3 crystal. It is thus seen that to package and miniaturize a complicated optical system into a single blook of crystal is possible..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1326 (1998)
A Virtual Network Model for the Errors Correction of Hardware System
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A virtual neural network model for correcting the errors of hardware system is proposed. The optical experimental results show that the virtual network can efficiently correct the errors of hardware system.A virtual neural network model for correcting the errors of hardware system is proposed. The optical experimental results show that the virtual network can efficiently correct the errors of hardware system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1332 (1998)
Spherical Light Source Based Shape from Shading Method
[in Chinese], and [in Chinese]
It will be very useful if shape recovery can be performed under indoor lights which maybe spherical shape. As a first step towards this goal a spherical light source model is developed for doing shape recovery. This model is more practical and convenient than other extended light source model. Base on it, the shape froIt will be very useful if shape recovery can be performed under indoor lights which maybe spherical shape. As a first step towards this goal a spherical light source model is developed for doing shape recovery. This model is more practical and convenient than other extended light source model. Base on it, the shape from shading method can be used to recover surface shape from one image. Our method is verified by both real and simulated experiments. The results show that this light source model is convenient and method for shape recovering is accurate..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1336 (1998)
Joint Transform Correlation Based on Double Second-Order Differentials
[in Chinese], [in Chinese], and [in Chinese]
An effective technique to improved joint transform correlation based on double second order differentials (2DJTC) is proposed. The process is able to extract image feactures and increase the contrast and extent of the fringes structure of joint transform power spectrum. The correlation performance of the proposed 1f reAn effective technique to improved joint transform correlation based on double second order differentials (2DJTC) is proposed. The process is able to extract image feactures and increase the contrast and extent of the fringes structure of joint transform power spectrum. The correlation performance of the proposed 1f real time optoelectronic hybrid correlator based on second differentiation (2DJTC) and compared with the binarized nonlinear joint transfrom correlator (BJTC). The results indicate that 2DJTC produces a reansonably good correlation performance..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1342 (1998)
The Iterative Algorithm of Digital Reconstruction of Coding Imaging
[in Chinese], [in Chinese], and [in Chinese]
The iterative algorithm of digital reconstruction of coding imaging is studied by matrix analysis. We use regularization method to overcome the ill posed problem. The convergence and error of the algorithm is studied. It is shown that the nosie can be compressed, but some local structure is distorted. The computation cThe iterative algorithm of digital reconstruction of coding imaging is studied by matrix analysis. We use regularization method to overcome the ill posed problem. The convergence and error of the algorithm is studied. It is shown that the nosie can be compressed, but some local structure is distorted. The computation complexity of the algorithm is analysed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1349 (1998)
Lasers and Laser Optics
Effect of Self-Generated Magnetic Field on Relativisic Harmonic Generation
[in Chinese], [in Chinese], and [in Chinese]
The effect of self generated magnetic field on relativisic harmonic generation is analysed. Results show that the self generated magnetic field excites even harmonics and influences the odd harmonics. Elaborate analysis of the second and the third harmonic generation shows that the self generated magnetic field excitesThe effect of self generated magnetic field on relativisic harmonic generation is analysed. Results show that the self generated magnetic field excites even harmonics and influences the odd harmonics. Elaborate analysis of the second and the third harmonic generation shows that the self generated magnetic field excites second harmonic radiation, weakens third harmonic ratiation, and prolongs dephasing time of them..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1355 (1998)
A Numerical Study of the Interaction Between High-Intensity Ultrashort Laser and Overdense Plasma
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The interaction between high intensity ultrashort laser and overdense plasma using a particle in cell simulation is numerically studied. The results show that irregular electric fields are excited in the plasma after the interaction, in the meantime, the temperature of some electrons in the plasmas are enhanced very hiThe interaction between high intensity ultrashort laser and overdense plasma using a particle in cell simulation is numerically studied. The results show that irregular electric fields are excited in the plasma after the interaction, in the meantime, the temperature of some electrons in the plasmas are enhanced very highly..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1359 (1998)
Damage of Optical Glass Materials with 2 ns Large Aperture High Power Laser
[in Chinese], and [in Chinese]
The surface damage thresholds of K8 glass and Nd glass exposed to 2 ns large size high power laser are measured with a Nomarski polarized light interferometer, and the damage mechanism is studied. The ultrasound wave induced by the stimulated Brillouin scattering(SBS) is found to dominate the damage at the nanosecond pThe surface damage thresholds of K8 glass and Nd glass exposed to 2 ns large size high power laser are measured with a Nomarski polarized light interferometer, and the damage mechanism is studied. The ultrasound wave induced by the stimulated Brillouin scattering(SBS) is found to dominate the damage at the nanosecond pulse laser radiation..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1362 (1998)
Bi_Directional Simultaneous Single-Longitudinal Model Lasing of a Er3+-Doped All-Fiber Ring Laser Using Composite Cavity
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A method to implement the bi directional simultansous single mode operation of fiber ring laser is proposed. Using the mode resonance characteristics of composite ring cavity and the mode decoupling between both clockwise and counter clockwise oscillating waves by the self built saturable absorption in a sub cavity undA method to implement the bi directional simultansous single mode operation of fiber ring laser is proposed. Using the mode resonance characteristics of composite ring cavity and the mode decoupling between both clockwise and counter clockwise oscillating waves by the self built saturable absorption in a sub cavity under weak pumping, a bi directional simultaneous single longitudinal mode Er 3+ doped all fiber ring laser is demonstrated..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1412 (1998)
Effects of Spectral Width of Frequency Selecting Element on Tunable External Cavity Semiconductor Lasers
[in Chinese], and [in Chinese]
It is known that the responding function of the tuning element in a tunable external cavity semiconductor laser (ECLD) has a finite spectral width. Effects of this finite width on the characteristics of the ECLD have been studied. Expressions of the upper bound of the spectral width and the frequency difference betweenIt is known that the responding function of the tuning element in a tunable external cavity semiconductor laser (ECLD) has a finite spectral width. Effects of this finite width on the characteristics of the ECLD have been studied. Expressions of the upper bound of the spectral width and the frequency difference between the peak of the grating reflection and the laser radiation have been derived for the case where a continuous tuning of the ECLD is required..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1417 (1998)
Thernal Design of a 100 W Copper Vapor Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The optimum input power density is presented by analyzing and calculating the discharge tube gas temperature of a 100 W copper vapor laser to avoid the “black center of beam”. The optimum thickness of alumina fiber can be determined by analyzing and calculating the coaxial heat conductivity loss. The theoretical calculThe optimum input power density is presented by analyzing and calculating the discharge tube gas temperature of a 100 W copper vapor laser to avoid the “black center of beam”. The optimum thickness of alumina fiber can be determined by analyzing and calculating the coaxial heat conductivity loss. The theoretical calculation is verified well with the experimental data. Therefore, the method of determining the gas temperature in discharge tube and the thickness of alumina fiber is built up..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1422 (1998)
Dynamic Measurement of Slope and Twist by Rotating Cone-Glass Speckle Shearography
[in Chinese]
The rotating cone glass speckle shearography used for dynamic measurement of slope and twist is discussed. The whole process can be recorded on a single specklegram. Optical systems are illustrated and experimental results are presented.The rotating cone glass speckle shearography used for dynamic measurement of slope and twist is discussed. The whole process can be recorded on a single specklegram. Optical systems are illustrated and experimental results are presented..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1426 (1998)
Study of Stark Effect Modulation with Doppler Broadening
[in Chinese], [in Chinese], and [in Chinese]
Theory of Stark effect modulation with Doppler broadening is analyzed by the semiclassical theory. Using a density matrix approach the absorption coefficient and modulation depth of NH 3 molecular near an absorption line has been formulated. The characteristic of Stark effect modulations at 10.784 μm was experimentallyTheory of Stark effect modulation with Doppler broadening is analyzed by the semiclassical theory. Using a density matrix approach the absorption coefficient and modulation depth of NH 3 molecular near an absorption line has been formulated. The characteristic of Stark effect modulations at 10.784 μm was experimentally investigated, modulation depth of 33% at 1 MHz was measured..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1430 (1998)
Materials
High Perfoemance MBDCG and Antihumidity Method by Molecule Modifing
[in Chinese], [in Chinese], and [in Chinese]
A high performance red sensitive dichromated gelatin holographic recording mateiral is studied. After its holograms are modified (taken off strong adsorbing humidity groups in gelatin), the holograms of high diffraction efficiency, which is stable in high humidity environment for long time, were obtained.A high performance red sensitive dichromated gelatin holographic recording mateiral is studied. After its holograms are modified (taken off strong adsorbing humidity groups in gelatin), the holograms of high diffraction efficiency, which is stable in high humidity environment for long time, were obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1449 (1998)
IR Luminescence Properties of Tm3+-Sensitized Ho3+in Fluoride Glass
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The infra red absorption spectrum of Tm 3+ and Ho 3+ ions in the fluoride glass was investigated. With a Ti∶sapphire laser as exciting source, the cross relaxation process of Tm 3+ ions and infra red emission spectra of Tm 3+ sensitized Ho 3+ ions were studied. The results indicate that the cross relaxation process occThe infra red absorption spectrum of Tm 3+ and Ho 3+ ions in the fluoride glass was investigated. With a Ti∶sapphire laser as exciting source, the cross relaxation process of Tm 3+ ions and infra red emission spectra of Tm 3+ sensitized Ho 3+ ions were studied. The results indicate that the cross relaxation process occurs only when the concentration of Tm 3+ ions is high (about 2 wt%). As the content of Ho 3+ ions increases, 2 μm emission intensity increases too. 2 μm emission intensity reaches maximum when the exciting wavelength is 813 nm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1454 (1998)
Nonlinear Optics
Study on Third-Order Nonlinearity of Azobezene Derivatives by Four-Wave Mixing
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The 3rd order nonlinear susceptibility χ (3) and response time of the azobenzene π conjugated derivatives are measured with the four wave mixing technique and picosecond frequency doubled Nd∶YAG laser (532 nm). The measured χ (3) and response time are 10 -9 esu and 20 ps, respectively. The mechanism of transient gratinThe 3rd order nonlinear susceptibility χ (3) and response time of the azobenzene π conjugated derivatives are measured with the four wave mixing technique and picosecond frequency doubled Nd∶YAG laser (532 nm). The measured χ (3) and response time are 10 -9 esu and 20 ps, respectively. The mechanism of transient grating effect and response time are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1290 (1998)
The Experimental and Analysis of Third-Harmonic Generation in KDP Crystal
[in Chinese], [in Chinese], and [in Chinese]
Third harmonic generation (THG) in KDP crystals was reported. Based on the experimental result, we analyzed and compared the contributions to KDP third order nonlinearity for direct THG process and cascading process. As a result, we discussed the possibility of using KDP as the standard in measuring the coefficient of Third harmonic generation (THG) in KDP crystals was reported. Based on the experimental result, we analyzed and compared the contributions to KDP third order nonlinearity for direct THG process and cascading process. As a result, we discussed the possibility of using KDP as the standard in measuring the coefficient of nonlinear optical crystals..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1295 (1998)
Optical Design and Fabrication
Imaging Resolution of Time Resolved Tomography in Tissues
[in Chinese], [in Chinese], and [in Chinese]
Resolution of time resolved imaging in tissues is calculated by using point spread function (PSF) with a diffusion model. The effects of temporal resolution of time gate, finite aperture of detector on image resolution are discussed in detail. Image resolution is also calculated as a function of depth of tissues and inResolution of time resolved imaging in tissues is calculated by using point spread function (PSF) with a diffusion model. The effects of temporal resolution of time gate, finite aperture of detector on image resolution are discussed in detail. Image resolution is also calculated as a function of depth of tissues and integration time..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1390 (1998)
Diffraction of a Small Aperture——Near-Field Optics Theory
[in Chinese], [in Chinese], and [in Chinese]
A general diffraction formula for circular apertures is derived. This formula is not limited by the aperture radius and the distance from the screen and can be used as a theory of near field optics. It satisfies the Maxwell′s scalar equations and Kirchhoff′s boundary conditions and includes propagating waves and evanesA general diffraction formula for circular apertures is derived. This formula is not limited by the aperture radius and the distance from the screen and can be used as a theory of near field optics. It satisfies the Maxwell′s scalar equations and Kirchhoff′s boundary conditions and includes propagating waves and evanescent waves. The numerical calculation shows that the results are better than those which are based on the Bethe model..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1395 (1998)
Dynamic Laser Outer Conical Refraction
[in Chinese], and [in Chinese]
Based on conical refraction effect of biarial crystal, the dynamic outer conical refraction with controllable cone apex angle and a kind of new method to implement the outer conical refraction are presented. The KNbO 3 crystal is used in the experiment, we have not only observed the outer conical refraction, but also oBased on conical refraction effect of biarial crystal, the dynamic outer conical refraction with controllable cone apex angle and a kind of new method to implement the outer conical refraction are presented. The KNbO 3 crystal is used in the experiment, we have not only observed the outer conical refraction, but also obtained the cone apex angle control from 0° to 8°..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1399 (1998)
Interferogram Processing System for Obstructed Aperture Interferometer
[in Chinese], [in Chinese], and [in Chinese]
A software for fringe processing of obstructed aperture interferometer is presented. The software can acquire the fringe data, fringe thinning and fit with expand Zernike polynomial, and give wavefront distribution and aberration. Because we have expanded the Zernike polynomial, the fitting result is improved.A software for fringe processing of obstructed aperture interferometer is presented. The software can acquire the fringe data, fringe thinning and fit with expand Zernike polynomial, and give wavefront distribution and aberration. Because we have expanded the Zernike polynomial, the fitting result is improved..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1404 (1998)
Light Flux on the Capillary Wall Shile Guiding a Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The light flux on the capillary wall while guiding a laser is simulated in ray tracing method. Calculated results indicate that the light flux on the capillary wall attenuated jumpily along its axis. In the same focus system, the flux decreased more rapidly when the radius of capillary is smaller and the taper angle isThe light flux on the capillary wall while guiding a laser is simulated in ray tracing method. Calculated results indicate that the light flux on the capillary wall attenuated jumpily along its axis. In the same focus system, the flux decreased more rapidly when the radius of capillary is smaller and the taper angle is larger. The light flux reduced more slowly when the F number of the focus len is larger, and the average flux is increased..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1408 (1998)
Optical Devices
Cascade Linearized Optical Modulator
[in Chinese], and [in Chinese]
The principle of cascade linearized optical modulator is discussed. The method of selecting modulator parameters is given out in detail. Compared with predistortion linearized modulator, cascade linearized optical modulator shows much advantages, such as stable character and convenient adjustment, so it is worthy of beThe principle of cascade linearized optical modulator is discussed. The method of selecting modulator parameters is given out in detail. Compared with predistortion linearized modulator, cascade linearized optical modulator shows much advantages, such as stable character and convenient adjustment, so it is worthy of being used widely..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1435 (1998)
Thermal-Optical Evaluation to Optical Windows of Space Camera
[in Chinese]
In the optical system of space camera, the optical window is the only optical component exposed to the very complicated thermal vacuum circumstance in orbit space. The temperature gradient occurs imperatively and then influences to the image quality and resolution of the space camera. Based on the theory of optical wavIn the optical system of space camera, the optical window is the only optical component exposed to the very complicated thermal vacuum circumstance in orbit space. The temperature gradient occurs imperatively and then influences to the image quality and resolution of the space camera. Based on the theory of optical wavefront error and combining the engineering practice, the thermal optical evaluation has been done to the optical window with non symmetric temperature field. The RMS wavefront errors of the optical window have been calculated on each typical position in orbit cycle. The results of the thermal optical evaluation in this paper are verified by the optical windows of American “Skylab” spaceship as a reference and a proof..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1440 (1998)
The Relationship Between Silicon Micromechanical Resonators and Excited Point
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The optically excited vibrations of silicon cantilever resonators are studied. We give the theoretical results and experimental results of cantilever′s coherent frequency and discuss the effect of excited point on the vibration of the cantilever. The amplitude of output signal is related with the position of optical exThe optically excited vibrations of silicon cantilever resonators are studied. We give the theoretical results and experimental results of cantilever′s coherent frequency and discuss the effect of excited point on the vibration of the cantilever. The amplitude of output signal is related with the position of optical excited point and the vibration mode. We can get the highest amplitude by selecting the center point of two nodal of the vibration mode, then the amplitude decreases with the optical beam move to the nodal of the mode, where we get the lower signal. This result is satisfied to other micromechanical resonators with point heating excitation..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1445 (1998)
Quantum Optics
Effects of One-Dimensional σ+-σ-Cooling and Re-Pumping Light on the Multi-Level Na Atoms in an One-Dimensional Magneto-Optical Trap
[in Chinese], and [in Chinese]
The formulas of populations distribution and Doppler cooling force dependent on the velocity of atoms in a non uniform magnetic field were described by considering the physical model of one dimensional σ + σ - cooling and repumping lights acting on 24 sub level of Sodium atoms. The influence of velocity dependent DopplThe formulas of populations distribution and Doppler cooling force dependent on the velocity of atoms in a non uniform magnetic field were described by considering the physical model of one dimensional σ + σ - cooling and repumping lights acting on 24 sub level of Sodium atoms. The influence of velocity dependent Doppler forces on the maximum capture speed and temperature of atoms were discussed at the conditions of different magnetic field, different intensities and detunings of repumping lights..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1281 (1998)
Observation of Doppler Shift of a Atomic Beam in Slow-Wave Field
[in Chinese], [in Chinese], and [in Chinese]
We report the Doppler shift of Na spectroscopy changing with the slow wave factor in a slow wave microwave field the reason of the phenomenon is discussed. The varity of the Doppler shift of the Na spectroscopy in a slow wave microwave field was observed experimentally, the spectroscopy at slow wave factors of 10.67 anWe report the Doppler shift of Na spectroscopy changing with the slow wave factor in a slow wave microwave field the reason of the phenomenon is discussed. The varity of the Doppler shift of the Na spectroscopy in a slow wave microwave field was observed experimentally, the spectroscopy at slow wave factors of 10.67 and 5.20 were respectively. It is demostated that the Doppler shift is direct proportion to the slow wave factor in the slow wave microwave field..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1286 (1998)
Rapid Communications
Absorption Increasing Optical Bistability Using Er-Doped Fiber
[in Chinese], [in Chinese], and [in Chinese]
The observation of increasing absorption nonlinearity and bistability without cavity in Er doped fiber is reported. The operation power is low (submillilatts). The mechanism of Er doped fiber in creasing absortion optical bistability is analysed.The observation of increasing absorption nonlinearity and bistability without cavity in Er doped fiber is reported. The operation power is low (submillilatts). The mechanism of Er doped fiber in creasing absortion optical bistability is analysed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1459 (1998)
Measurement of Dynamic Parameters of the Excited States (21Π0) in Na2
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By means of two photon resonant three photon ionization spectroscopic technique, ionization spectrum of X 1Σ + g→2 1Π g of the sodium dimer in range of ( 16574.5～16590.5 ) cm -1 was detected and its three resonant ionization features were identified. With the measurement of ion current decay curves of the three featureBy means of two photon resonant three photon ionization spectroscopic technique, ionization spectrum of X 1Σ + g→2 1Π g of the sodium dimer in range of ( 16574.5～16590.5 ) cm -1 was detected and its three resonant ionization features were identified. With the measurement of ion current decay curves of the three features, dynamic parameters of them were obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1464 (1998)
Obtaining Hollow Beam Using Dislocation Grating
[in Chinese], [in Chinese], and [in Chinese]
The interference pattern between a screw wave and a plane wave is investigated and the diffraction gratings were synthesized with the aid of a computer. Using the synthesized gratings with different orders, hollow beam of different sizes is obtained.The interference pattern between a screw wave and a plane wave is investigated and the diffraction gratings were synthesized with the aid of a computer. Using the synthesized gratings with different orders, hollow beam of different sizes is obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1467 (1998)
Numerical Simulation of Propagation of Diffuse Reflection Light of Extended Object
[in Chinese], and [in Chinese]
The propagation of diffuse reflection light of an extended object is numerically simulated. It is shown that propagation and imaging of the paraxial diffuse reflecting light near optical axis of the receiving telescope can be calculated by the paraxial scalar wave equation and phase screen algorithm. The turbulent effeThe propagation of diffuse reflection light of an extended object is numerically simulated. It is shown that propagation and imaging of the paraxial diffuse reflecting light near optical axis of the receiving telescope can be calculated by the paraxial scalar wave equation and phase screen algorithm. The turbulent effects on the image propagation are calculated and discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1470 (1998)
Spectroscopy
Study on Lineshape of Zeeman Modulation Magnetic Rotation Spectroscopy
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The ellipticity of incident light is considered as an important factor of the Zeeman modulation magnetic rotation spectroscopy (ZM MRS), by which all the lineshapes measured before are explained. The observed lineshapes of Zm MRS agree with the theoretical predicition, and the analysis is very helpful to imptove the meThe ellipticity of incident light is considered as an important factor of the Zeeman modulation magnetic rotation spectroscopy (ZM MRS), by which all the lineshapes measured before are explained. The observed lineshapes of Zm MRS agree with the theoretical predicition, and the analysis is very helpful to imptove the measuring accuracy of ZM MRS..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 18, Issue 10, 1300 (1998)
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