Contents
2005
Volume: 25 Issue 12
27 Article(s)
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Atomic and Molecular Physics
Ionic Structure and Spectrum Analysis of Au47+ and Au53+ in Au Laser Plasma
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on the extended relativistic multi-configuration Dirac-Fock theory, with quantum electrodynamical (QED) effect and Breit correction, transition wavelengths, transition probabilities and oscillator strengths of Au47+ and Au53+ have been calculated with the General-purpose Relativistic Atomic Structure Program (GRABased on the extended relativistic multi-configuration Dirac-Fock theory, with quantum electrodynamical (QED) effect and Breit correction, transition wavelengths, transition probabilities and oscillator strengths of Au47+ and Au53+ have been calculated with the General-purpose Relativistic Atomic Structure Program (GRASP2). Fermi nuclear model of two parameters, extended-average-level model, configuration interaction and electric dipole transition have been considered in the program. The wavelengths obtained are in good agreement with the experimental data available. It is found that the transition of 3d-4f is the stronger transition channel. These data provide reference valuable for level lifetime, charge state distribution and average ionization degree of Au plasma..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1585 (2005)
Fiber Optics and Optical Communications
Supercontinuum Spectrum Generation in an Optical Fiber with a Concave Dispersion Profile
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The supercontinuum (SC) spectra generated are compared in dispersion decreasing fibers (DDF) with different dispersion profile. Results show that DDF with concave dispersion profile is more beneficial to generate flat and broad SC spectra, when the dispersion profile of the fiber is symmetrical to central wavelength anThe supercontinuum (SC) spectra generated are compared in dispersion decreasing fibers (DDF) with different dispersion profile. Results show that DDF with concave dispersion profile is more beneficial to generate flat and broad SC spectra, when the dispersion profile of the fiber is symmetrical to central wavelength and decreases from anomalous dispersion region to normal with propagation distance. Optical pulses propagation in fibers has been studied by utilizing total field formation in the frequency field. It is found that optical pulse can be compressed more extensively in anomalous dispersion region, furthermore, optical spectra can be further broadened because there exits a zero-dispersion wavelength in normal dispersion region, leading to the generation of a flatter and broader SC spectra. The spectral bandwidth can reach 298 nm when relative spectral intensity is -27 dB, which is 97 nm broader than that in a convex dispersion profile fiber under the same situation. It is proved by numerical calculation that DDF with concave dispersion profile can generate broader spectrum than that in DDF with convex dispersion profile under the same conditions..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1590 (2005)
Coupling Mode Theory of Acousto-Optic Fiber Devices with Four Ports
[in Chinese], [in Chinese], and [in Chinese]
The acoustic-induced refraction index change in optic fiber is introduced simply. Based on the composite waveguide theory, the difference between the general fiber coupler and the null coupler is discussed, and the latter in essence acts like a section of two-mode fiber which can be exciting separately. From the coupliThe acoustic-induced refraction index change in optic fiber is introduced simply. Based on the composite waveguide theory, the difference between the general fiber coupler and the null coupler is discussed, and the latter in essence acts like a section of two-mode fiber which can be exciting separately. From the coupling mode theory, the asymptotic acoustic-induced coupling-mode equations in null coupler is resolved, and a complete analytic expression for power conversion between the fibers is given out firstly. With that, the frequency shift characteristics and functions provided with this kind of device at resonance frequency are explained. In the end, an experimental study on an acousto-optic tunable splitter or a switch is reported..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1595 (2005)
Holography
Improvement of Sensitivity and Refractive-Index Changes in Holographic Recording in Doubly Doped LiNbO3 with UV Light
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A nonvolatile recording method with double modulated UV beams in (Ce,Cu)∶LiNbO3 crystals is proposed. Compared with the normal UV-sensitized nonvolatile holographic system, the amplitude of the refractive-index changes is greatly increased and the recording sensitivity is largely enhanced by recording with UV light in A nonvolatile recording method with double modulated UV beams in (Ce,Cu)∶LiNbO3 crystals is proposed. Compared with the normal UV-sensitized nonvolatile holographic system, the amplitude of the refractive-index changes is greatly increased and the recording sensitivity is largely enhanced by recording with UV light in the (Ce,Cu)∶LiNbO3 crystals. Temporal evolutions of the photorefractive grating and the diffraction efficiency are effectively described and numerically analyzed based on jointly solving the two-center material equations and the coupled-wave equations. Roles of doping levels and recording-beam intensity in the process are discussed in detail. Investigations show that gratings recorded in the deep and shallow centers are in phase, the value of the total grating (the superimposition of the deep and shallow gratings) is the summation of those of the two gratings; in the fixing phase, the depth of grating in the deep center is enhanced; the amplitude of the refractive-index changes increases with increasing the concentrations of the deep and shallow centers, and larger recording intensity results in the stronger total grating and the larger value of the recording sensitivity. Theoretical results can confirm and predict experimental results..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1600 (2005)
Image Processing
Study on Two-Orthogonal-View Reconstruction Algorithm of Optical Computerized Tomography
[in Chinese], and [in Chinese]
Two-orthogonal-view reconstruction algorithm based on maximum entropy theory is proposed. Multi-peaks asymmetrical flow fields can be well reconstructed by the proposed reconstruction algorithm according to two-orthogonal-views projection data. Additional prior information with axial symmetrical gene is combined into tTwo-orthogonal-view reconstruction algorithm based on maximum entropy theory is proposed. Multi-peaks asymmetrical flow fields can be well reconstructed by the proposed reconstruction algorithm according to two-orthogonal-views projection data. Additional prior information with axial symmetrical gene is combined into the new algorithm, the prior information can be calculated by the two-orthogonal-views projection data, and the effect of projection angel factor is analyzed. The numerical simulation results show that reconstructed results of multi-peaks asymmetrical flow fields obtained by the proposed algorithm are superior to the traditional alborithm, and the double-peak-cosine-Gauss simulated field root-mean-square error decreases 73%. Three-peak-random-Gauss simulated field root-mean-square error decreases 47%. So the proposed novel algorithm strongly shows superiority to reconstructing multi-peaks asymmetrical flow fields. Meanwhile only projection data two of orthogonal directions are needed so the experiment system is simplified..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1606 (2005)
Image Reconstruction with High Resolution in X-Ray Coded Aperture Imaging
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In the processing diagnosis of the inertiat confinement fusion (ICF), the ring coded aperture imaging technique is applied to gain high-space and time resolutions simultaneously. The key of acquiring high-spatial resolution is to obtain the point spread function of the imaging system correctly. The common method, firstIn the processing diagnosis of the inertiat confinement fusion (ICF), the ring coded aperture imaging technique is applied to gain high-space and time resolutions simultaneously. The key of acquiring high-spatial resolution is to obtain the point spread function of the imaging system correctly. The common method, firsthand projection method, neglects the X-ray diffraction effect, so the resolution of reconstructed image is decreased. Considering the X-ray diffraction effect the point spread function (PSF) of the ring coded aperture is derived from the scalar diffraction theory. And the Wiener filter is fabricated on the basis of the PSF. In National Key Laboratory of Laser Fusion, the imaging experiment on the diagnosis of ICF is completed using a ring coded aperture plate with inner diameter d1=250 μm and outer diameter d2=260 μm. The obtained coded image is processed by the Wiener filter where the diffractive effect is considered. The acquired reconstructive image by author's method is better than the image by the firsthand projection method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1611 (2005)
Imaging Systems
Study of Optimization and Imaging Characteristics of Two-Dimensional Circle Array for Optical Synthetic Aperture System
[in Chinese], [in Chinese], and [in Chinese]
Optical synthetic aperture imaging system applies the interferometric method to sample object in the spatial frequency domain and retrieve the image whose spatial resolution is much higher than that of monolithic aperture by inverse Fourier or other numerical transformation. An optimized synthetic aperture array which Optical synthetic aperture imaging system applies the interferometric method to sample object in the spatial frequency domain and retrieve the image whose spatial resolution is much higher than that of monolithic aperture by inverse Fourier or other numerical transformation. An optimized synthetic aperture array which is composed of a number of identical sub-aperture located at a circle can provide a roughly uniform distributed and no-redundant sampling coverage in two-dimensional spatial frequency domain, which can form a high quality and snapshot imaging system. An optimization method called simulated annealing is adopted for the optimization of a two-dimensional circle aperture array composed of 7～16 sub-apertures. Based on principle of optical diffraction imaging, imaging characteristics of the optimized arrays as well as arrays distributed evenly composed of N sub-apertures at a two-dimensional circle are analyzed in detail by using computer simulation in both spatial domain and frequency domain. The simulated computation results of the arrays composed of 7～16 sub-apertures show that the optimized array has better quality of image than the arrays of distributed sub-aperture in both point spread function and optical transfer function. Besides, the bigger the size and the more the number of sub-aperture, the better the imaging is. But, on the other hand, although higher resolution can be obtained with bigger size of the circle synthesized by a number of sub-aperture, improved imaging quality is refused..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1616 (2005)
Stereo Image Matching for Digital Close-Range Photogrammetry Based on Gray-Scale Projection
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
For the purposes of three-dimensional modeling of buildings, a new stereo image matching algorithm based on the gray-scale projection is advanced considering the characteristics of the digital close-range photogrammetry. The algorithm extends the one-dimensional gray-scale projection from two directions to four directiFor the purposes of three-dimensional modeling of buildings, a new stereo image matching algorithm based on the gray-scale projection is advanced considering the characteristics of the digital close-range photogrammetry. The algorithm extends the one-dimensional gray-scale projection from two directions to four directions. The gray-scale projections in the column, row, major diagonal and secondary diagonal directions are calculated simultaneously. The weighted average of similarity measure of these four one-dimensional projection vectors between the left image and right image is computed for the final matching decision. Homonymous epipolar lines are found by using the relative orientation linear transformation (RLT). To decrease the searching scope and improve the matching accuracy, an improved dynamic bounding approach is proposed to control the searching scope of sequential points in the point list to be matched along the homonymy epipolar-line. The new algorithm is applied to actual stereo images of a building taken by a digital close-range photogrammetric system and the experimental result shows that the algorithm has a higher matching speed and matching accuracy than the pyramid image matching algorithm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1623 (2005)
Instrumentation, Measurement and Metrology
Error Evaluation of Cosine Dependent Algorithm in Precision Interference Measurement
[in Chinese], [in Chinese], and [in Chinese]
Aiming at the application of precision length measurement, the error of phase-shifting algorithm based on the cosine dependent algoritm by means of double-beam interference is explored, and the precision formula of intensity distribution of multiple-beam interference (multiple reflection and transmission by the opticalAiming at the application of precision length measurement, the error of phase-shifting algorithm based on the cosine dependent algoritm by means of double-beam interference is explored, and the precision formula of intensity distribution of multiple-beam interference (multiple reflection and transmission by the optical surface) with the basic principle of interference optics is derived. Based on this formula and the numerical analysis, the maximum error of the interference intensity is found to reach 14.4% due to ignoring the second multiple-beam interference in the precision measurement, and the different dependences between the reflection coefficients of the two surface and the phase difference for the four-step algorithm and the five-step algorithm are listed: the latter possesses higher accuracy than the former since the former is more sensitive to the intensity error; and the error of the algorithm can be ignored while the reflection coefficient of the two surfaces or one of them is low, unless the reflectivity of the two surfaces is high..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1629 (2005)
Lasers and Laser Optics
Single-Stage Fiber Raman Lasers for Pupming Fiber Raman Amplifiers
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The pumping source is the key technology of fiber Raman amplifiers applied in dense wavelength division multiplexing systems. A compact 1342 nm Nd3+∶YVO4 diode-pumped solid state laser(DPSSL) module pumped by 808 nm laser diodes is developed. A single-stage 1.4 μm fiber Raman laser is constructed by pumping a single-stThe pumping source is the key technology of fiber Raman amplifiers applied in dense wavelength division multiplexing systems. A compact 1342 nm Nd3+∶YVO4 diode-pumped solid state laser(DPSSL) module pumped by 808 nm laser diodes is developed. A single-stage 1.4 μm fiber Raman laser is constructed by pumping a single-stage fiber Raman resonator based on fiber Bragg gratings with such 1342 nm diode-pumped solid-state laser module. The threshold property, the optimized setup of the diode-pumped solid-state laser module and the design scheme of the single-stage fiber Raman resonator are analyzed respectively. The diode-pumped solid-state laser module is presented with the total laser power of 655 mW and the slope efficiency of 42.6% pumped by a 2 W 808 nm laser diode. The light power conversion slope efficiency of the single-stage fiber Raman resonator achieves 75% and the total laser power at 1425 nm, 1438 nm, 1455 nm and 1490 nm achieves 300 mW each. Finally, a broadband, flat-gain distributed fiber Raman amplifier pumped by such lasers is presented..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1634 (2005)
Green He-Ne Laser with Internal Cavity
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By making use of the needle method, the coating design of green He-Ne laser with internal cavity and the spectrum performance of the designed coating are introduced. The newly designed films of green He-Ne laser have been coated by making use of ion beam sputtering deposition, and the measured results have been given oBy making use of the needle method, the coating design of green He-Ne laser with internal cavity and the spectrum performance of the designed coating are introduced. The newly designed films of green He-Ne laser have been coated by making use of ion beam sputtering deposition, and the measured results have been given out. Many types of green He-Ne laser with internal cavity have been fabricated and the related techniques have been discussed. In these green He-Ne lasers, the lasers with cavity length of 420 mm have typical output power of 3 mW (single mode), the lasers of 360 mm have typical output power of 2 mW (single mode), the lasers of 240 mm have typical output power of 1 mW (single mode), and the small and short lasers with cavity length of 100 mm have also typical output power of 0.1 mW..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1639 (2005)
Materials
Fabrication of CdTe Polycrystalline Films and Their Properties
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The structure and characteristics of CdTe thin films are dependent on the whole deposition process in closed-space sublimation system (CSS) in working atmosphere of Ar and O2. It is helpful for preparation of thin and compact CdTe thin films with fine photoelectric characteristics to study the heat exchange and mass trThe structure and characteristics of CdTe thin films are dependent on the whole deposition process in closed-space sublimation system (CSS) in working atmosphere of Ar and O2. It is helpful for preparation of thin and compact CdTe thin films with fine photoelectric characteristics to study the heat exchange and mass transportation in CSS process. Here, the physical mechanism of CSS is analyzed, the temperature distribution in CSS system is measured, and the dependence of preliminary nucleus creation on increasing-temperature process and pressure is studied. The results indicate that the samples depositing in the different pressure are all cubical structure of CdTe with the diffraction peaks of CdS and SnO2∶F. With the gas pressure increasing, the crystal size of CdTe decreases, the transmission of the thin film goes down and the absorption side shifts to the short-wave direction. So the increasing-temperature curve has been optimized, and with the analysis integrated solar cells of better conversion efficiency in configuration of SnO2∶F/CdS/CdTe/Au are achieved..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1644 (2005)
Plasma Resonance Absorption Properties of the Ag-AAO Nano-Array Composite
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Plasma resonance absorption properties of the Ag-AAO nano-array composite are studied. The spectral analysis shows that the surface plasma resonance peak of Ag occurs at λ=352～377 nm. As the Ag composition decreases, the dipolar plasma resonance absorption peak shifts to the longer wavelength,weakened and gradually expPlasma resonance absorption properties of the Ag-AAO nano-array composite are studied. The spectral analysis shows that the surface plasma resonance peak of Ag occurs at λ=352～377 nm. As the Ag composition decreases, the dipolar plasma resonance absorption peak shifts to the longer wavelength,weakened and gradually expanded, and vice versa. The theoretical analysis shows that the M-G calculated results agree well with the experimental ones..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1649 (2005)
Effect of Gamma Irradiation on the Spectral Properties of Undoped and Eu3+-Doped Y2SiO5 Single Crystals
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The absorption spectra of undoped and Eu3+-doped Y2SiO5 single crystals before and after gamma irradiation were studied. Additional absorption peaks at 260～270 nm and 320 nm were observed in irradiated Y2SiO5 crystal with no annealing or hydrogen-annealing, which were respectively caused by F centers and O- centers. OwThe absorption spectra of undoped and Eu3+-doped Y2SiO5 single crystals before and after gamma irradiation were studied. Additional absorption peaks at 260～270 nm and 320 nm were observed in irradiated Y2SiO5 crystal with no annealing or hydrogen-annealing, which were respectively caused by F centers and O- centers. Owing to the abserence of oxygen vacancy, there was no absorption peaks of color centers in air-annealed Y2SiO5 crystal. Additional absorption band of Eu2+ ions, which peaked at 300 nm and 390 nm, were produced in irradiated and H2-annealed Eu3+∶Y2SiO5 crystal, except absorption bands of F centers and O- centers. Additional absorption increased with irradiation dose increasing. Air-annealing could decrease the concentration of color centers, and the H2-annealing could increase it..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1655 (2005)
Upconversion Luminescence of Tm3+/Yb3+ Codoped Oxyfluoride Glasses Ppumped at 970 nm
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new oxyfluoride glass system was developed with molar fractions of n(SiO2)=0.30,n(PbF2)=0.50,n=(Al2O3)=0.15,n(AlF3)=(0.049-x),n(TmF3)=y,n(YbF3)=x(x=0,0.001,0.010,0.015,0.020,y=0,0.001) and its upconversion emission properties were investigated. Furthermore the upconversion mechanism was discussed. The experimental reA new oxyfluoride glass system was developed with molar fractions of n(SiO2)=0.30,n(PbF2)=0.50,n=(Al2O3)=0.15,n(AlF3)=(0.049-x),n(TmF3)=y,n(YbF3)=x(x=0,0.001,0.010,0.015,0.020,y=0,0.001) and its upconversion emission properties were investigated. Furthermore the upconversion mechanism was discussed. The experimental results showed that there was not upconversion emission for Tm3+ singly doped glasses under 970 nm excitation. While strong blue (452 nm, 476 nm), red (647 nm) and near infrared (971 nm) emissions were found in Tm3+/Yb3+ codoped glasses, which responded to the following radiative transition: 1D2→3F4, 1G4→3H6, 1G4→3F4 and 3H4→3H6. Moreover, the intensity of upconversion luminescence was strongly dependent on the concentration of Yb3+. It was indicated that under 970 nm excitation the upconversion luminescence intensity of Tm3+ increased with Yb3+ sensitizing. With Yb3+ concentration increasing, absorption of pump source and energy transfer between Tm3+ and Yb3+ were both enhanced, and as a result the upconversion luminescence intensity was increased..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1659 (2005)
Medical Optics and Biotechnology
Study on the Fundamental of the Laser High-Precision Microsurgery
[in Chinese], [in Chinese], and [in Chinese]
The precision of laser-microsurgery is often limited by thermal and thermomechanical collateral damages. Adjusting the pulse width of the laser to the thermal relaxation time of the absorbing construction can avoid thermal side effects and facilitate a selective treatment of the selective cells. Conjugates of colloid gThe precision of laser-microsurgery is often limited by thermal and thermomechanical collateral damages. Adjusting the pulse width of the laser to the thermal relaxation time of the absorbing construction can avoid thermal side effects and facilitate a selective treatment of the selective cells. Conjugates of colloid gold and bovine intestinal alkaline phosphatase (AP) are presented as the model system for investigating protein inactivation in the vicinity of strongly absorbing nanoparticles, and under certain conditions the protein can be denatured and the membrane permeabliltiy can be increased with the irradiation of the nanosecond and picosecond laser. Calculations show that under irradiation of nano- or picosecond laser pulses gold particles of submicrometer size can easily be heated to several hundred kelvins, the thermal effects is confined in a space less than tens of nanometers. The mechanism of denaturalized protein is analyzed with this laser-based absorpting nanopartide technology..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1664 (2005)
Model for Elastic Light Scattering from Nucleated Cells
[in Chinese], [in Chinese], and [in Chinese]
A model is presented to calculate the light scattering properties of nucleated cells which are mimiced by two concentric ellipsoids (CEM). The light-scattering characteristics are explored, deriving from the Rayleigh-Debye-Gans approximation and by simultaneous application of field averaging of the internal field and mA model is presented to calculate the light scattering properties of nucleated cells which are mimiced by two concentric ellipsoids (CEM). The light-scattering characteristics are explored, deriving from the Rayleigh-Debye-Gans approximation and by simultaneous application of field averaging of the internal field and modification of the propagation constant inside the different cellular compartments. It is shown that the CEM is superior to the ball model. CEM can reflect the true configuration of the nonspherical nucleated cells more accurately. In addition, the simultaneous detection of the light-scattering intensities in the forward-, lateral-, and back-scattering directions can help distinguish the different cell types in heterogeneous population of nucleated cells, so it can be well used in cell classification and research of cell transfiguration..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1670 (2005)
Nonlinear Optics
Unusual Photonic Tunneling in Multilayer System with a Negative Refraction Index Layer
[in Chinese], [in Chinese], and [in Chinese]
The optical character of the multiplayer system with a negative refractive index layer is investigated. By means of a transfer matrix method, the exact analytical expression of transmissivity has been derived. Unusual photonic tunneling in the multilayer system with a negative refraction index layer has been analyzed. The optical character of the multiplayer system with a negative refractive index layer is investigated. By means of a transfer matrix method, the exact analytical expression of transmissivity has been derived. Unusual photonic tunneling in the multilayer system with a negative refraction index layer has been analyzed. For all frequency and incident angle, if all parameter are matching, the transmittance reaches unity. When only the backdrop is not matching, the transmittance is independent of the incident wavelength, but depends on the incident angle. For the TM wave, there is a special angle, known as Brewster's angle, with which the transmittance reaches unity, and a larger refractive index of the end will enlarge the transmittance. When the thickness or the refractive index of the medial layer is mismatching, the transmittance distributed symmetrically about the mismatching position decays with the increase of the disharmony, and there appears a faster decay when the incident angle increases..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1676 (2005)
Optical Devices
Investigation on the Liquid Crystal Spatial Light Modulator with High Precision and Pure Phase
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A liquid crystal spatial light modulator (LC SLM) with parallel alignment TFT is prepared, the theory of which is also discussed. And properties of the modulation are theoretically calculated. Measurements are conducted on properties of the phase modulation and the amptitude modulation. The results indicate that it is A liquid crystal spatial light modulator (LC SLM) with parallel alignment TFT is prepared, the theory of which is also discussed. And properties of the modulation are theoretically calculated. Measurements are conducted on properties of the phase modulation and the amptitude modulation. The results indicate that it is a pure phase modulator in the range of the gray level. Its precision is measured on a ZYGO interferometer. The experiments show that on the area of 1 cm×1 cm the peak to valley (PV) value is up to 0.098λ, RMS up to 0.017λ, and the depth of modulation up to 0.6λ after correction. A grating configuration with the phase differences of π/2 is accordingly generated, which shows that the phase of light can be medulated with it quite well..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1682 (2005)
Aberration Decoupling Analysis for Double Deformable Mirrors Adaptive Optical System
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A theoretical study of the aberration decoupling and the algorithm of aberration limited for a double mirrors adaptive optical system including a large scale stroke deformable mirror and a high spatial frequency deformable mirror is presented. By adding a limitative aberration vector in the gradient response matrix of A theoretical study of the aberration decoupling and the algorithm of aberration limited for a double mirrors adaptive optical system including a large scale stroke deformable mirror and a high spatial frequency deformable mirror is presented. By adding a limitative aberration vector in the gradient response matrix of high spatial deformable mirror, the voltage of actuators of two deformable mirrors is calculated, and the two deformable mirrors can correct the low-order aberration and high-order aberration respectively. The situation that double deformable mirrors in an adaptive optical system correct the low-order aberration and high-order aberration respectively has been simulated. The result indicates that the close-loop correction performance of double deformable mirrors adaptive system is almost the same as that of the adaptive optical system with an ideal stroke deformable mirror..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1687 (2005)
Single Long-Period Grating Based on Michelson Interferometer
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A Michelson interferometer based on a single long-period fiber grating (LPFG) is presented. The input signal is partly coupled into the cladding of the fiber by LPFG, and the pigtail of the LPFG is coated with high reflection film (RF). Therefore, both of the transmitted optical signals in the core and cladding are couA Michelson interferometer based on a single long-period fiber grating (LPFG) is presented. The input signal is partly coupled into the cladding of the fiber by LPFG, and the pigtail of the LPFG is coated with high reflection film (RF). Therefore, both of the transmitted optical signals in the core and cladding are coupled simultaneously back to the LPFG and interfere by the HR coating. The interference characteristics are analyzed theoretically. The fringe-shift of the interference spectrum shows good linear relationship to the temperature, which is measured to be 31.3 pm/℃ in the experiment. The proposed device is expected to serve a high temperature sensor, as well as WDM filter..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1693 (2005)
Quantum Optics
Light Squeezing of the System of the Two-Mode Odd-Even Entangled Coherent States Field Interacting with a Three-Level Atom
[in Chinese], and [in Chinese]
By means of solving Schrdinger equation and numerical calculations, the light squeezing effects in the system of the two-mode odd-even entangled coherent optical field interacting with a V-type three-level atom discussed. The results indicate that the light squeezing effects depend on the degree of entanglement of theBy means of solving Schrdinger equation and numerical calculations, the light squeezing effects in the system of the two-mode odd-even entangled coherent optical field interacting with a V-type three-level atom discussed. The results indicate that the light squeezing effects depend on the degree of entanglement of the two-mode odd-even entangled coherent optical fields, the detuning, the mean photon numbers and the atomic initial state. If the two-mode entangled coherent optical field is in unentangled states, its squeezing value is larger than that of the two-mode entangled coherent optical field in entangled states. When the atom is prepared in ground state or excited state initially, there appear obvious squeezing effects for the coherent optical field. On the contrary, if the initial state atom is prepared in ground state and excited state with adjacent amplitude, the squeezing effects in the system of the two-mode odd-even entangled coherent optical field will vanish. Whenever the optical fields are in entangled states or not, the squeezing effects will appear with two coherent states having the same mean photon number..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1697 (2005)
Quantum Fluctuation Power Spectrum of Optical Field in One-Dimensional Absorbing and Dispersive System
[in Chinese], [in Chinese], and [in Chinese]
The electromagnetic field is quantized in absorbing and dispersive dielectrics by Green's function method, and the quantum theory of the optical field is investigated one-dimensional system consisted of three-layered absorbing and dispersive dielectrics. The power spectrum of quantum fluctuations of the optical fieThe electromagnetic field is quantized in absorbing and dispersive dielectrics by Green's function method, and the quantum theory of the optical field is investigated one-dimensional system consisted of three-layered absorbing and dispersive dielectrics. The power spectrum of quantum fluctuations of the optical field in the dispersion and absorption dielectrics cavity is given by the fluctuation-dissipation theorem, and the effect of the dispersive and absorbing character of the dielectrics on the workability of an optical system is discussed by numerical caculation. The result shows that the working state of a system is connected with the frequency of the optical field. Absorbing and dispersive character of the dielectrics in every area influences not only the power spectrum of the electric field fluctuation of its ambient region, but also the other side's. There is an important meaning for exploring the pratical applications of the complicated dielectric distribution and structural system in optical communication, modern optic-engineering and microwave technology in the result..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1702 (2005)
Rapid Communications
Fabrication of Soft X-Ray Phase Condenser Zone Plates
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Soft X-ray zone plate is an important element which has the function of concentration, dispersion and imaging in soft X-ray optics. An Au condenser phase zone plate mask is fabricated using holography and ion beam etching process. Soft X-ray Ge and Ni condenser phase zone plates are fabricated by ion-beam etching technSoft X-ray zone plate is an important element which has the function of concentration, dispersion and imaging in soft X-ray optics. An Au condenser phase zone plate mask is fabricated using holography and ion beam etching process. Soft X-ray Ge and Ni condenser phase zone plates are fabricated by ion-beam etching technology on polyimide substrate and contact synchrotron radiation lithography with the mask..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1722 (2005)
Scattering
Thermal Wave Multiple Scattering by Subsurface Cylinders
[in Chinese], [in Chinese], and [in Chinese]
Based on non-Fourier's law of heat conduction, by using the expansion method of wave functions, the thermal wave scattering by subsurface cylinders in the opaque body is investigated. A general solution of multiple scattered waves in solids based on wave equations of heat conduction is given. The thermal wave is exBased on non-Fourier's law of heat conduction, by using the expansion method of wave functions, the thermal wave scattering by subsurface cylinders in the opaque body is investigated. A general solution of multiple scattered waves in solids based on wave equations of heat conduction is given. The thermal wave is excited at surfaces of opaque materials by modulated optical beams. The circular cylinder is taken as a cavity with thermal insulation conditions. The effects of different geometric and physical parameters on the temperature distribution, and especially the effect of thermal wavelength on the temperature are analyzed. The model can be applied to the infrared radiometry technique and photothermal wave imaging. And also it can be used to determine the distribution of the defects by the laser detector..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1707 (2005)
Spectroscopy
Dependence of the Raman Spectrum of Porous Silicon on Laser Power
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Raman spectra of as-prepared porous silicon are obtained using 457.5 nm solid-state laser from which some relations between peak parameters and laser powers are also got. The experimental phenomena of the Raman peaks near 520 cm-1 and 300 cm-1 are extensively explained. The red-shift and asymmetrically broadening of thRaman spectra of as-prepared porous silicon are obtained using 457.5 nm solid-state laser from which some relations between peak parameters and laser powers are also got. The experimental phenomena of the Raman peaks near 520 cm-1 and 300 cm-1 are extensively explained. The red-shift and asymmetrically broadening of the Raman peaks near 520 cm-1 and 300 cm-1, which are reversible with the increase and decrease of the laser powers, are thought to be derived from quantum confinement effect (QCE) when the mean particle size shrinks as local temperature increases, and this obeys the basic rule of thermodynamics. The apperarance of double peaks near 520 cm-1 at high powers are thought to be the cleavage of longitudinal optical (LO) and transverse optical (TO) modes when the mean particle size reaches a certain threshold..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1712 (2005)
Study on the Spectral Radiometric Calibration Method of the Spatially Modulated Imaging Fourier Transform Spectrometer
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Spatially modulated imaging Fourier transform spectrometer (SMIFTS) was different from other spectrometers. It gained one dimensional spatial information and one dimensional spectral information. Calibration of spatially modulated imaging Fourier transform spectrometer was imperfect for its special theory. A method of Spatially modulated imaging Fourier transform spectrometer (SMIFTS) was different from other spectrometers. It gained one dimensional spatial information and one dimensional spectral information. Calibration of spatially modulated imaging Fourier transform spectrometer was imperfect for its special theory. A method of radiometric calibration is introduced, which used spatially modulated imaging Fourier transform spectrometer and spectral radiometer to collect irradiance of the same target. After converted interferograms into spectrum and compared with the true spectrum collected by spectial radiometer, calibration coefficients were obtained and the calibration accuracy was analysed. The results indicated that the method can satisfy the requirement of spectral radiometric calibration by spatially modulated imaging Fourier transform spectrometer, the calibration accuracy reached 5.74％..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 12, 1718 (2005)
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