Contents
2005
Volume: 25 Issue 5
32 Article(s)
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Atmospheric Optics and Oceanic Optics
The Principle Analysis of Passive Detection of Upper Atmospheric Wind Field of the Lorentzian Profile
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
hrough detecting the Doppler shifts of airglow (aurora) in upper atmosphere, the physical quantity such as velocity, temperature and pressure of upper atmosphere is derived. Taking the aurora (two major lines of the emission of the atomic oxygen) in upper atmosphere as the detection source, the detection principle and hrough detecting the Doppler shifts of airglow (aurora) in upper atmosphere, the physical quantity such as velocity, temperature and pressure of upper atmosphere is derived. Taking the aurora (two major lines of the emission of the atomic oxygen) in upper atmosphere as the detection source, the detection principle and method of the line based on the Lorentzian profile are researched; the distribution of the velocity, temperature and pressure and their calculation formula are given out based on the Lorentzian profile, using computer imitation, the error curve is described, so it is shown that the Lorentzian profile is very important in the upper atmospheric wind detection..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 577 (2005)
Noise Suppression Algorithm of Coherent Ladar Range Image
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Ladar, which can obtain range image and intensity image, may provide much useful information than other imaging system. Range image noise suppression is a key for ladar image processing. The suppression effects influence directly precision in tracking and pointing. According to range image noise, combining intensity imLadar, which can obtain range image and intensity image, may provide much useful information than other imaging system. Range image noise suppression is a key for ladar image processing. The suppression effects influence directly precision in tracking and pointing. According to range image noise, combining intensity image with multilevel median filtering is used for actual ladar image. First, dropout is removed according to intensity image mean in 3×3 window and whole image mean. Then, outlier is removed by using multilevel median filter. Each processing result is presented and better range image is obtained. The investigation results show that this algorithm can suppress range image noise in coherent ladar effectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 581 (2005)
Geometric Optics
Mitigating Damage of the Ghost in High Power Laser Facilities by Real-Ray Trace
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Ghost reflections are a major consideration in the optical design of the high-power laser facilities. A thorough ghost analysis has been carried out for the technical integration line (TIL), which is the full scale prototype for Shenguang-Ⅲ laser facility (SG-Ⅲ), with a method of combination of paraxial ray tracing andGhost reflections are a major consideration in the optical design of the high-power laser facilities. A thorough ghost analysis has been carried out for the technical integration line (TIL), which is the full scale prototype for Shenguang-Ⅲ laser facility (SG-Ⅲ), with a method of combination of paraxial ray tracing and real ray tracing. This paper takes one of the “dangerous surfaces” as example, which is the front plane of a window in Pockels cell, simulating the energy distribution graph on it by numerous real-ray tracings. According to the shape of ghost energy graph and its corresponding optical structure, suggestions are made to effectively mitigate the damage on the studied optical surfaces..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 585 (2005)
A Study on Universal Ray Tracing Algorithm in the Medium of Variable Refractive Index
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An algorithm of ray tracing based on light ray refraction and reflection in geometrical optics in the medium of variable refractive index is proposed and a recursive direction-cosine equation of reflected light and refractive light for ray tracing in the medium of variable refractive index is carried out, In the algoriAn algorithm of ray tracing based on light ray refraction and reflection in geometrical optics in the medium of variable refractive index is proposed and a recursive direction-cosine equation of reflected light and refractive light for ray tracing in the medium of variable refractive index is carried out, In the algorithm, some problems, confirmation of normal line, light turning etc., are resolved. At last its correctness is validated by comparing numerical value and analytic value of several different special distribution of refractive index of analytic solution, furthermore some problems in the during of applying the algorithm and under solution in the algorithm are discussed. Not only the algorithm has extensive feasibility and is independent of distribution of refractive index, but also its numeric precision is about 10-5. The application of the algorithm is prospective in the many cases, such as optical designing and spatial imaging compensation of variable refractive index..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 589 (2005)
Image Processing
Study on Adjustable Image Fusion Method for Remote Sensing
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Most of the commonly used image fusion methods have the same limitation, only one fused result is possible by using each of the method, the users have no control over how much spatial detail or spectral information should be retained. A wavelet-based adjustable image fusion method is presented. The two images are decomMost of the commonly used image fusion methods have the same limitation, only one fused result is possible by using each of the method, the users have no control over how much spatial detail or spectral information should be retained. A wavelet-based adjustable image fusion method is presented. The two images are decomposed into sub-images with wavelet transform, respectively. By introducing two parameters that can adjust the fused image, these sub-images are fused in wavelet space. A fused image is achieved by inverse wavelet transform. To compare the performances of the proposed method with those of the commonly used image fusion methods, such as the usual wavelet fuser, the intensity-hue-saturation (IHS) fuser, and the principal component analysis (PCA) fuser, the SPOT and the landsat thematic mapper (TM) images are used to perform the experiment. The results show that the balance between spectral characteristics preservation and high spatial resolution retention can be achieved at different levels in image fusion. With some combination of the parameters, the visual effects and the statistical parameters indicate that the fused results are slightly better than those of the commonly used image fusion methods..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 593 (2005)
Remote Sensing Image Fusion Based on Steerable Pyramid Frame Transform
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In order to integrate two registered high spatial resolution panchromatic image and low spatial resolution multispectral image of the same scene, a new remote sensing image fusion algorithm based on a novel steerable pyramid frame transform (SPFT) is proposed. Each band of the multispectral image is combined with the pIn order to integrate two registered high spatial resolution panchromatic image and low spatial resolution multispectral image of the same scene, a new remote sensing image fusion algorithm based on a novel steerable pyramid frame transform (SPFT) is proposed. Each band of the multispectral image is combined with the panchromatic image. In the individual band fusion, histogram matching is first performed on the panchromatic image to obtain a new high spatial resolution image with a uniform histogram as the band to be fused of the multispectral image. Then, the histogram matched panchromatic image and the band to be fused of the multispectral image are both decomposed by the SPFT. The SPFT coefficients are combined to produce the composite coefficients. Finally, the fused image of the panchromatic image and the band to be fused of the multispectral image is obtained by performing inverse SPFT. Experimental results show that the proposed image fusion algorithm outperforms the traditional methods based on the intensity-hue-saturation (IHS) transform and discrete wavelet frame transform (DWFT), especially in situations where the source images are not perfectly registered..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 598 (2005)
Instrumentation, Measurement and Metrology
Application of Wavelet Transform Profilometry in Bi-Frequency Grating Fringe
[in Chinese], and [in Chinese]
In order to overcome the discontinous phase unwrapping problems existing in the shape measurement of the discontinuous objects, the spatial carrier grating fringe pattern produced by the computer of which the ratio of two frequencies is an irrational number, is introduced. By using the wavelet transform profilometry, tIn order to overcome the discontinous phase unwrapping problems existing in the shape measurement of the discontinuous objects, the spatial carrier grating fringe pattern produced by the computer of which the ratio of two frequencies is an irrational number, is introduced. By using the wavelet transform profilometry, the wrapped phase distribution corresponding to the two frequencies respectively in one bi-frequency grating pattern is got. And then applying the phase unwrapping by a lookup table method for unwrapping, the determinate modulated phase distribution corresponding to the two frequencies is got. The technique can tolerate the height discontinuity of the shape of the objects. The defailed theoretical deduction, experimental verification and an example of 3-D shape measurement are shown..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 603 (2005)
Highly Accurate Calibration of Optical Radiation Based on Cryogenic Radiometer at Visible and Near Infrared Spectrum (488～944 nm)
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Report the research on highly calibraton and standard transfer is based on cryogenic with analyzing the component uncertainties which contribute to total uncertainty associated with the measurement results. Firstly, the laser power was measured by cryogenic radiometer in visible and near infrared spectral regions (488～Report the research on highly calibraton and standard transfer is based on cryogenic with analyzing the component uncertainties which contribute to total uncertainty associated with the measurement results. Firstly, the laser power was measured by cryogenic radiometer in visible and near infrared spectral regions (488～944 nm), uncertainty of power measurement is less than 0.016%. Secondly, Si transfer standard detectors were directly calibrated against the cryogenic radiometer using laser source, therefore the absolute spectral responsivity scale is established at this spectral regions (488～944 nm) at uncertainty less than 0.028%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 609 (2005)
Error Analysis on Three-Waveplate Polarization State Transformers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The polarization transform errors of three-waveplate polarization transformers (TWPTs), which consist of one half-waveplate (λ/2) and two quarter-waveplates (λ/4), are discussed detail. The error models of the TWPT using a new and simple two dimensions geometry method instead of traditional Poincaré sphere method The polarization transform errors of three-waveplate polarization transformers (TWPTs), which consist of one half-waveplate (λ/2) and two quarter-waveplates (λ/4), are discussed detail. The error models of the TWPT using a new and simple two dimensions geometry method instead of traditional Poincaré sphere method are deduced and numerically calculated. The results of investigation show that the errors of the TWPTs are dependent on the different combinations of one λ/2 and two λ/4, and according to the accuracy of TWPTs, λ/4+λ/2+λ/4 is the best, λ/2+λ/4+λ/4 is better and λ/4+λ/4+λ/2 is good. After polarization transform, the errors of azimuth angle and ellipticity angle are rather large and minor respectively and the TWPTs have enough accuracy to meet the applications in the field of coherent optical communications and optical fiber communication systems..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 614 (2005)
Lasers and Laser Optics
A Far-Field Distribution Model Describing the Double-Peak Beam of High-Power Laser Diodes
[in Chinese], [in Chinese], and [in Chinese]
In order to design optical system to collimate laser beam, its far-field distribution should be acquired exactly. Based on the Helmholtz equation, two decentered Gauss beams are used to represent the distribution of the source in the direction of paralleling the chip plane, then a new model describing the double-peak bIn order to design optical system to collimate laser beam, its far-field distribution should be acquired exactly. Based on the Helmholtz equation, two decentered Gauss beams are used to represent the distribution of the source in the direction of paralleling the chip plane, then a new model describing the double-peak beam of high-power laser diodes is presented. A comparison with several practical devices is also made, satisfying result has been obtained, the rate of the error power to the total is only 1%～2%. Because of its simple structure, this model can be used to design shaping system or analyze the propagation properties when the laser beam passes through a optic system, and helpful for calculating coupling efficiency..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 619 (2005)
Experimental Study for an Arched Diode-Side-Pumped Nd∶YAG Lasers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The characterization of an arched diode-side-pumped Nd∶YAG laser was reported. A concentric-pumping and concentric-cooling close configuration was used for the laser. The pump light distribution and temperature profile were calculated and optimized. Influence of the laser diode chirp and sag on the laser output, the efThe characterization of an arched diode-side-pumped Nd∶YAG laser was reported. A concentric-pumping and concentric-cooling close configuration was used for the laser. The pump light distribution and temperature profile were calculated and optimized. Influence of the laser diode chirp and sag on the laser output, the effect of thermal birefringence on the laser Q-switch output and laser output under different resonator length and different cavity have been studied. A maximum output of 135 mJ in multimode Q-switch operation is obtained with pumped energy 735 mJ (marked value). The pulse width is 7.6 ns and the full divergence angle is smaller than 1.5 mrad. The slope efficiency is 44.3%. The optical-optical efficiency is 18.4%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 623 (2005)
Materials
The Test and Analysis for Thermo-Optic Effect of Silicon Resin
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The calorescence coefficients of silicon resin reached -3.6×10-4 /℃ at 650 nm, and -3.3×0-4 /℃ at 632.8 nm which were tested by V prism device. A silicon resin waveguide is formed on a quartz substrate and its effective refractive indexes N at different temperatures are detected by coupled prism method. The tThe calorescence coefficients of silicon resin reached -3.6×10-4 /℃ at 650 nm, and -3.3×0-4 /℃ at 632.8 nm which were tested by V prism device. A silicon resin waveguide is formed on a quartz substrate and its effective refractive indexes N at different temperatures are detected by coupled prism method. The thickness h and refractive index n1 of the film at different temperatures are calculated and these results show that the variety of N comes from the n1 and the reflection angle of guided wave on the boundary. The experimental results of waveguide reveal that the larger calorescence coefficients of silicon resin are induced by the larger orientational polarizability of the molecules in the material and it can be useful in making the thermo-optic switch of low power dissipation in short-range networks..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 629 (2005)
Investigation of Color Centers in Sapphire Induced by Neutrons Irradiation
[in Chinese], [in Chinese], and [in Chinese]
Neutron-irradiation induced defects formation and optical properties change in sapphire (α-Al2O3) are discussed. Czochralski (CZ) and temperature gradient technique (TGT) grown sapphire crystals are irradiated by neutrons, and F, F+ and F+2 color centers are formed in both crystals according to absorption and fluoresceNeutron-irradiation induced defects formation and optical properties change in sapphire (α-Al2O3) are discussed. Czochralski (CZ) and temperature gradient technique (TGT) grown sapphire crystals are irradiated by neutrons, and F, F+ and F+2 color centers are formed in both crystals according to absorption and fluorescence spectra. But the concentration of color centers is different. Concentration of F+ center in TGT crystals is higher than that in CZ samples, while the F center concentration in CZ crystals is higher than that in TGT crystal. It is attributed to different impurities concentration of sapphire samples. Obvious thermoluminescence peaks at 145 ℃ and 150 ℃ are found in CZ and TGT grown sapphire crystals respectively. With calculation by initial elevation method, thermoluminescence trap depths of two crystal samples are 1.15 eV and 1.05 eV, respectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 633 (2005)
Medical Optics and Biotechnology
Photonics Diffusion for Small Source-Detector Separations of Tissue
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new control parameter is introduced to phase function to modify the general diffusion approximation for small source-detector separation of tissue. The results of standard diffusion approximation, general diffusion approximation and modified general diffusion approximation are compared with the Monte-Carlo simulationA new control parameter is introduced to phase function to modify the general diffusion approximation for small source-detector separation of tissue. The results of standard diffusion approximation, general diffusion approximation and modified general diffusion approximation are compared with the Monte-Carlo simulation in steady state diffusion equation for slab boundary condition. The result shows that the modified general diffusion approximation with an appropriate control parameter is more closed to Monte-Carlo simulation for local tissue, and describes exactly the photon propagation of small separation between source and detector. The effects of system parameters, such as numerical aperture and diameter of laser on the control parameter are also discussed. This study is useful for the measurement of optical properties of tissue with high resolution..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 638 (2005)
Protective Effect of Vitamin C on Ultraviolet Radiation-Induced DNA Damage
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The protection effect of vitamin C on ultraviolet radiation-induced DNA damage was discussed. The Raman spectra of the mixture of small amount vitamin C and DNA sdution with ultraviolet radiation of 9 min and 30 min were measured. The intensity of ultraviolet radiation is 18.68 W/m2. When vitamin C (0.2 mmol/L) was addThe protection effect of vitamin C on ultraviolet radiation-induced DNA damage was discussed. The Raman spectra of the mixture of small amount vitamin C and DNA sdution with ultraviolet radiation of 9 min and 30 min were measured. The intensity of ultraviolet radiation is 18.68 W/m2. When vitamin C (0.2 mmol/L) was add ed to DNA solution, ultraviolet radiation only had a slightly influence on the DNA. Though free radicals generated by ultraviolet radiation in the mixture of DNA solution and vitamin C can cause DNA damage, vitamin C has antioxidative property and it can scavenge free radicals and prevent the reaction between DNA and free radicals. In the other way, both vitamin C and DNA have strong absorbancy at 260 nm ultraviolet. Maybe the vitamin C absorbancy of ultraviolet radiation is stronger than DNA′s, so DNA was protected..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 643 (2005)
Nonlinear Optics
Amplitude Optical Pupil Filters with Sine FunctionsXiao Fanrong
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Optical pupil filter is one of the basic elements for optical superresolution. So it is important to design and manufacture the optical pupil filter. The amplitude optical pupil filters with sine functions were designed. This pupil filter can realize different types of superresolution by changing the periods of sine fuOptical pupil filter is one of the basic elements for optical superresolution. So it is important to design and manufacture the optical pupil filter. The amplitude optical pupil filters with sine functions were designed. This pupil filter can realize different types of superresolution by changing the periods of sine function or the transmittance of the central point. By numerical calculations, It is noticed that 0.5～2 sine periods is suitable for superresolution. When the number of periods is smaller than 0.5, there is no superresolution effect. And the superresolution effect is worse as the number bigger than 2. In numerical calculation it is also noticed that the Strehl ratio is unchanged with the central point transmittance when the number of periods is integer and its value is 0.25. The numerical results show the typical properties of amplitude optical pupil filters with sine functions and it will help manufacture it..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 647 (2005)
Study of Quasi-Phase-Matched Cascaded χ(2) All-Optical Wavelength Conversion
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A novel all-optical wavelength conversion (AOWC) based on the cascaded sum frequency generation (SFG) and difference frequency generation (DFG) in LiNbO3 waveguides have been theoretically studied. This novel wavelength convertor employing two pump sources places the two input pump wavelengths outside the optical commuA novel all-optical wavelength conversion (AOWC) based on the cascaded sum frequency generation (SFG) and difference frequency generation (DFG) in LiNbO3 waveguides have been theoretically studied. This novel wavelength convertor employing two pump sources places the two input pump wavelengths outside the optical communication band. It is easily realize optimum coupling between punp wavelengths and signal wavelength since their wavelengths are relatively close to each other and the pump wavelenths do not occupy the communication band and the convertor has a characteristic of polarization-insensitive. The theoretical model of the AOWC is established and the coupled-mode equations of optical interaction in waveguide are given out. Then the solutions of coupled-mode equations are in detail deduced step by step and an electric field expression of clear physical insight is obtained. The effects of the device length and the pump powers on the conversion efficiency are analyzed, and it offers theoretical foundation for the optimum frabrication parameters for stable and highly efficient AOWC..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 651 (2005)
Theoretical Studies on Frequency-Dispersion Effect of First Hyperpolarizabilities of Hemicyanine Derivatives
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The first hyperpolarizabilities β(-2ω;ω,ω) and β(-ω;ω,0) of hemicyanine derivatives chromophore, 4-N,N-dimethylamino-4'-N'-methyl stilbazolium (DAS), are calculated by using time-dependent Hartree-Fock (TDHF) and sum over states (SOS) method at infrared wavelength, respectively. Frontier molecular orbitals are The first hyperpolarizabilities β(-2ω;ω,ω) and β(-ω;ω,0) of hemicyanine derivatives chromophore, 4-N,N-dimethylamino-4'-N'-methyl stilbazolium (DAS), are calculated by using time-dependent Hartree-Fock (TDHF) and sum over states (SOS) method at infrared wavelength, respectively. Frontier molecular orbitals are also computed by INDO/CI method. The numerical results indicate that maximum absorption wavelengh is about 480 nm which agrees well with the experimental data, and nonlinear optical properties are determined by the first excited state. In infrared region (800～2500 nm), with the increase of fundamental frequency, secondary harmonic generation (SHG) β(-2ω;ω,ω) and electrooptic effect (EOE) β(-ω;ω,0) also become larger, but β(-2ω;ω,ω) increased greater than β(-ω;ω,0). In off-infrared region, β(-2ω;ω,ω) dispersion curve is flat while sharp caused by resonance enhancement in near-infrared region (<1300 nm). β(-2ω;ω,ω) equals to (380±5)×10-30 esu at 1064 nm calculated by TDHF. However, for the higher frequency, other excited states should be considered in SOS calculation. Moreover, influence of basis set effect upon TDHF calculation is also discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 655 (2005)
OPTOELECTRONICS
Design and Modification of Double Channel of One-Dimensional Photonic Crystal
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new way for designing one-dimensional photonic crystal, which has double-channel, is given by researching the characteristics of Fabry-Perot filter and analyzing the influence of thickness change of defect layers on the number and the position of the channels. A double-symmetrical structure consisted of one-dimensionA new way for designing one-dimensional photonic crystal, which has double-channel, is given by researching the characteristics of Fabry-Perot filter and analyzing the influence of thickness change of defect layers on the number and the position of the channels. A double-symmetrical structure consisted of one-dimensional photonic crystal is introduced based on the Fabry-Perot structure. The position of the two channel series in the photonic forbidden band is separately adjusted by changing the thickness of three defect layers in the double-symmetrical structure. The equivalent surface method is used in the elementary calculation and the computer simulation is used to further modify the thickness of the layer. With this design, the interference of different channels is avoided and the independent change of the channel position is realized in the double-sysmmetrical one-dimensional photonic crystal..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 661 (2005)
Guide Modes in Magnetic Photonic Crystal Heterostructures Composed of Different Lattices
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The photonic-band-gap (PBG) structures of two-dimensional magnetic photonic crystals (MPCs) are investigated by using the plane wave expansion (PWE) method. One is composed of rectangular magnetic pillars embedded into host dielectric in rectangular lattice (RR type), the other consists of circle magnetic cylinders embThe photonic-band-gap (PBG) structures of two-dimensional magnetic photonic crystals (MPCs) are investigated by using the plane wave expansion (PWE) method. One is composed of rectangular magnetic pillars embedded into host dielectric in rectangular lattice (RR type), the other consists of circle magnetic cylinders embedded into host dielectric in triangular lattices (TC type). The changes of PBG structures corresponding to the magnetic permeability are presented, and each sample is found with large ratio of gap-midgap. Based on the above results, the PBG structure of magnetic heterostructures composed of both RR type and TC type MPCs (MRRTC heterostructures) is investigated by use of PWE method combined with the supercell technique. The guide modes at the interface of MRRTC heterostructures are produced at absolute PBG without longitndinal gliding or displacement of the lattice. When introducing the relatively longitudinal gliding and transverse displacement of the lattice from the interface, the dispersion curves of guide modes vary apparentely..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 665 (2005)
Physical Optics
The Research of Thermal Effect on the Rotatory Power of Quartz
[in Chinese], and [in Chinese]
Using ceramic plate semiconductor refrigerator as temperature control unit the thermal effect of the rotatory power of quartz crystal is investigated. The testing system for the thermal effect of the rotatory power of quartz crystal is designed and the rotatory power at different temperature ranging from -10 to 60 ℃ isUsing ceramic plate semiconductor refrigerator as temperature control unit the thermal effect of the rotatory power of quartz crystal is investigated. The testing system for the thermal effect of the rotatory power of quartz crystal is designed and the rotatory power at different temperature ranging from -10 to 60 ℃ is measured. The results show that, for given homogeneous light,the rotatory power increases with increasing temperature. Through Sellmeier equation and quartic fit method, the relation of Sellmeier equation's coefficient to temperature is calculated, thereby the rotatory power of quartz crystal at different wavelength and random temperature can be obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 670 (2005)
Goos-Hnchen Shift of the Transmitted Light Beam in a Two-Prism Configuration
[in Chinese], [in Chinese], and [in Chinese]
Goos-Hnchen (GH) shifts of the transmitted and reflected light beam in a two-prism configuration is staturated to a maximum in the opaque limit for the incidence angle above the critical angle for total reflection. The magnitude of GH shift is about the order of the wavelength. The Goos-Hnchen shift of the transmitteGoos-Hnchen (GH) shifts of the transmitted and reflected light beam in a two-prism configuration is staturated to a maximum in the opaque limit for the incidence angle above the critical angle for total reflection. The magnitude of GH shift is about the order of the wavelength. The Goos-Hnchen shift of the transmitted light beam in a two-prism configuration is investigated by stationary-phase approach when the incidence angle is less than the critical angle. It is shown that the Goos-Hnchen shift of the transmitted light beam in propagating case is a periodical function of the air-gap thickness, incidence angle and the refractive index of two prisms. Due to transmission resonance, the Goos-Hnchen shift of the transmitted light beam can be of one or two order of wavelength. Compared to the result for the incidence angle above the critical angle, the Goos-Hnchen shift presented here can be resonantly enhanced by boundary interaction effect. It is also shown that the Goos-Hnchen shift of the reflected light beam is the same as that of the transmitted one in the symmetric structure, when the resonance does not occur. These resonance-enhanced shifts of the transmitted light beam may lead to potential applications in the optical devices, such as optical switch and optical coupler..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 673 (2005)
Rapid Communications
Research on an Offset-type Micro Mechanical Variable Optical Attenuator
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A variable optical attenuator (VOA) fabricated by micro mechanical technology is presented. Based on micro electromagnetic actuation, the attenuation level is adjusted by changing the radial offset between the input and output optical fiber. The structure parameter was determined through optics, mechanics and magnetic A variable optical attenuator (VOA) fabricated by micro mechanical technology is presented. Based on micro electromagnetic actuation, the attenuation level is adjusted by changing the radial offset between the input and output optical fiber. The structure parameter was determined through optics, mechanics and magnetic circuit analysis. The device was fabricated and packaged by micromachining technology. The packaged volume of the device is 20 mm×15 mm×8 mm. According to the experiment results, the insertion loss is less than 1 dB, the polarization relevant loss is less than 0.1 dB, dynamic range is larger than 35 dB and the driving voltage is less than 5 V. It promises to be a low cost, high performance passive device for all-optical-networks..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 717 (2005)
Highly Efficient Bright Red Organic Electrophosphorescent Device
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A highly efficient bright red electrophosphorescent device using bis(2-methyl-8-quinolinato)4-phenylphenolate aluminum (BAlq) as a hole and exciton blocker is reported. Maximum luminance and external quantum efficiency of the device are 10362 cd/m2 and 7.0% respectively. Commission Internationale de l′Eclairage (CIE) cA highly efficient bright red electrophosphorescent device using bis(2-methyl-8-quinolinato)4-phenylphenolate aluminum (BAlq) as a hole and exciton blocker is reported. Maximum luminance and external quantum efficiency of the device are 10362 cd/m2 and 7.0% respectively. Commission Internationale de l′Eclairage (CIE) co-ordinates are (0.672, 0.321). In addition, the quantum efficiency is still as high as 4.3% at a current density of 100 mA/cm2. The device can satisfy the requirement of the red in the full color dynamic displays..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 719 (2005)
Spectroscopy
he Emission Spectrum of Plasma Induced by Pulsed Laser Ablation of HgCdTe
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
At different pressure, a pulsed laser was used to irradiate the surface of Hg0.8Cd0.2Te. The emission spectrum from the plasma was detected by a time and space-resolved diagnostic technique. The velocity of the ejected particle was measured on the basis of obtained time of flight spectrum. The experimental results indiAt different pressure, a pulsed laser was used to irradiate the surface of Hg0.8Cd0.2Te. The emission spectrum from the plasma was detected by a time and space-resolved diagnostic technique. The velocity of the ejected particle was measured on the basis of obtained time of flight spectrum. The experimental results indicate that the velocity of the ejected particle decreases quickly with increasing the distance from target surface. Moreover, the velocity is influenced greatly by the ambient pressure and the laser energy has almost no impact on velocity. In addition, the electron density was estimated by using full width at half maximum and the results show that the electron density decreases quickly during a short period after the laser arrives the surface. Moreover, the maximal electron density emerges at a position which is some distance away from the target surface but not on the surface..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 678 (2005)
Photoluminescence Excitation Spectra and Absorption Spectra Analysis of CdSeS Quantum Dots
[in Chinese], [in Chinese], and [in Chinese]
The sub-structure in absorption spectrum was analyzed by means of photoluminescence excitation (PLE) spectra. The glass samples of CdSeS quantum dots were prepared by co-melting and analyzed by means of high resolution transmission electron microscopy (HRTEM), the annealing time was 2 h and 4 h respectively, the quantuThe sub-structure in absorption spectrum was analyzed by means of photoluminescence excitation (PLE) spectra. The glass samples of CdSeS quantum dots were prepared by co-melting and analyzed by means of high resolution transmission electron microscopy (HRTEM), the annealing time was 2 h and 4 h respectively, the quantum dots' diameter was 3.6 and 3.8 nm respectively. Absorption spectra and photoluminescence excitation spectra were measured at room temperature. The absorption spectra showed quantum size-dependent effects. Two peaks were observed in photoluminescence excitation spectra. The valence band degeneracy and the interaction between electrons and holes were taken into account, the energies of 1S3/2-1Se and 2S3/2-1Se transitions versus quantum dots' radii were obtained by theoretical analysis and numerical calculation. The two peaks in photoluminescence excitation spectra are assigned to 1S3/2-1Se and 2S3/2-1Se transitions, respectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 683 (2005)
Analysis of Dissolved Organic Matter in Water Using Spectral Fluorescent Signature
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An analytical method of fast diagnosing organic matter in water is discussed. The concepts of total luminescence spectroscopy (TLS) and spectral fluorescent signature (SFS) technique are introduced. The total luminescence spectroscopy of water samples in combination with laser induced fluorescence (LIF) measurements usAn analytical method of fast diagnosing organic matter in water is discussed. The concepts of total luminescence spectroscopy (TLS) and spectral fluorescent signature (SFS) technique are introduced. The total luminescence spectroscopy of water samples in combination with laser induced fluorescence (LIF) measurements using 532 nm wavelength excitation source are measured in the laboratory, and the spectral characteristics of dissolved organic matter (DOM) and chlorophyll a (Chl a) are analysed with spectral fluorescent signature technique. The curve of normalized fluorescence intensity against corresponding concentration of humic acid is showed. The possibilities of water quality monitoring in real time and on line based upon spectral fluorescent signature technique are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 687 (2005)
Optical Heterodyne-Magnetic Rotation-Concentration Modulation Spectroscopic Technique
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new spectroscopic technique for measuring the spectrum of transient molecules, named optical heterodyne magnetic rotation enhanced concentration modulation spectroscopy (OH-MR-CMS) is introduced. It combines optical heterodyne detection and magnetic rotation spectroscopy with the concentration modulation technique leA new spectroscopic technique for measuring the spectrum of transient molecules, named optical heterodyne magnetic rotation enhanced concentration modulation spectroscopy (OH-MR-CMS) is introduced. It combines optical heterodyne detection and magnetic rotation spectroscopy with the concentration modulation technique leading to greatly improved sensitivity. The concentration modulation spectroscopy (CMS) is suitable for the detection of the spectrum of short-lifetime transient molecules and excited state molecules. The optical heterodyne (OH) technique is used for eliminating the amplitude fluctuation noise from the laser source so as to realize the detection limit of the shot noise. The magnetic rotation (MR) technique makes a selective detection of paramagnetic molecules, so as to further improve the detection sensitivity. The principle of OH-MR-CMS is interpreted in detail and the technique is used to measure the absorption spectrum of the O2 b1Σ+g-X3Σ-g forbidden transition with a quite good signal-to-noise (S/N) ratio. The detailed analysis of the sensitivity of this technique is presented, the minimum relative absorption is approximately 1.9×10-9 and the absorption cross-section σ of the O2 forbidden transition is 2.4×10-24 cm2..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 691 (2005)
Thin Films
Analysis of Polarization Aberration in Projection System
[in Chinese], [in Chinese], and [in Chinese]
Optical thin films exhibit inevitable polarization effects at oblique incidence. When illuminating light with a large numerical aperture incident on dichroic thin films at a non-normal angle in Philips prism system, linear polarized light is turned into elliptical polarized light because of the difference of the phase Optical thin films exhibit inevitable polarization effects at oblique incidence. When illuminating light with a large numerical aperture incident on dichroic thin films at a non-normal angle in Philips prism system, linear polarized light is turned into elliptical polarized light because of the difference of the phase shift between s- and p-polarization component. Polarization aberration in projection display system is analyzed based on the theory of Jones matrix polarization ray tracing. The dark-state output and extinction ratio of system are also calculated. Furthermore, the character of polarized light on the exit pupil is given out, and the variation of polarization aberration at different F-number illumination light is analyzed. At last, the influence of monitoring errors of thin film on the polarization aberration is analyzed. The monitoring errors have great impact on the polarization aberration and contrast of the system. The method can be applied to other large aperture optical systems..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 696 (2005)
Design and Character Analysis of Multi-Layer Dielectric Film Used in Pulse Compressed Gratings
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Pulse compressed gratings (PCG) used in chirped-pulse amplification system and based on multi-layer thin film stack are etched with ion-beam and holographic techniques. Diffraction efficiency and laser induced damage threshold are determined by the structure of the parameter of gratings, on the other hand, by the desigPulse compressed gratings (PCG) used in chirped-pulse amplification system and based on multi-layer thin film stack are etched with ion-beam and holographic techniques. Diffraction efficiency and laser induced damage threshold are determined by the structure of the parameter of gratings, on the other hand, by the design of multi-layer dielectric greatly. A multi-layer dielectric stack design used at 1053 nm and exposed at 413.1 nm is given. The influence of the structure on the optical character is described in detail. The analysis shows that H3L (H2L)9H0.5L2.03H films meet the requirements of PCG. The sample was prepared by ZZX-800 vacuum machine with e-beam gun, and its optical character is given. Transmittance is less than 0.5% at using wavelength and above 90% at exposing wavelength. Results show that the optical property is excellent and there is a good agreement between the measured transmittance and the design..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 701 (2005)
Algorithm of Seeking Precise Refractive Index Value of Spacer for Controlling Angle-Tuned Filter′ Polarization Characteristics
[in Chinese], [in Chinese], and [in Chinese]
Central wavelength of S-polarization and P-polarization will separate when the filter is tilted .But the central wavelength of two polarization components in angle-tuned filter can be coincided by adjusting effective refractive index of spacer.Beginning with the analysis of phase relationship and by use of the characteCentral wavelength of S-polarization and P-polarization will separate when the filter is tilted .But the central wavelength of two polarization components in angle-tuned filter can be coincided by adjusting effective refractive index of spacer.Beginning with the analysis of phase relationship and by use of the characteristic matrix expression of multilayer films, two implicit function expressions of middle layer's refractive index of spacer and central wavelength of P-polarization and S-polarization are deduced. Therefore the value of middle layer's refractive index and corresponding central wavelength can be quickly and accurately obtained. Simulation calculations of two concrete filter designs for single cavity and three cavities prove that the method is feasible. Based on the samples data analysis of difference curves with incidence angle from 0° to 30°, it is proven that the algorithm is highly accurate..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 707 (2005)
X-Ray Optics
X-Ray Reflectivities and FWHM of Hg1-xCdxTe/Cd1-zZnzTe Materials
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The computer simulation of X-ray rocking curve is an important method for characterization for the semiconductor materials. The calculation of the intrinsic rocking curve is the foundation of its simulation. The intrinsic reflectivities of Hg1-xCdxTe and Cd1-zZnzTe materials are calculated by using X-ray dynamic theoryThe computer simulation of X-ray rocking curve is an important method for characterization for the semiconductor materials. The calculation of the intrinsic rocking curve is the foundation of its simulation. The intrinsic reflectivities of Hg1-xCdxTe and Cd1-zZnzTe materials are calculated by using X-ray dynamic theory and the effect of compositions and thicknesses on intrinsic reflectivities and full width at half maximum (FWHM) is studied. It is found that intrinsic reflectivities and FWHM of Hg1-xCdxTe and Cd1-zZnzTe materials depend on their compositions and thicknesses. The reflectivities and FWHM are determined by X-rays scattering and absorption in the materials. If the film thicknesses are smaller than penetration depth, the changes of the shape of the intrinsic rocking curves, intrinsic reflectivities and FWHM are also affected by theirs. If the thickness of Hg1-xCdxTe films is larger than 7 μm, the changes of the intrinisic reflectivities and FWHM of the (333) diffraction plane would be very small..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 25, Issue 5, 712 (2005)
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