Journals >Acta Photonica Sinica
Contents
2005
Volume: 34 Issue 10
39 Article(s)
Export citation format
Research Article
Temperature Modeling of Intracavity Doubling Frequency Nonlinear Crystal
, , , , and
In order to improve harmonic conversion efficiency and eliminate walk-off effect,temperature field of nonlinear crystal was accurately calculated. Through work state analysis of KTP crystal with intracavity doubling frequency,a thermal model of rectangle nonlinear crystal was buildt and the radiation eccentricity (RE) In order to improve harmonic conversion efficiency and eliminate walk-off effect,temperature field of nonlinear crystal was accurately calculated. Through work state analysis of KTP crystal with intracavity doubling frequency,a thermal model of rectangle nonlinear crystal was buildt and the radiation eccentricity (RE) of a rectangle crystal was first defined. Based on heat conductive equation,a general analytical solution of temperature model was obtained and the temperature model influenced by eccentric radiated of fundamental wave was first investigated.
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1441 (2005)
Study on the Necessary Minimum Diffraction Efficiency of Acoustooptical Q-switched Laser
, , , ... and |Show fewer author(s)
A four-level system is analyzed as an example,and the necessary minimum diffraction efficiency of acoustooptical Q-switched laser in a certain output pulse energy is studied. Through soluting the population inversion density , the relationship between a certain output pulse energy and cavity loss,the necessary minimum A four-level system is analyzed as an example,and the necessary minimum diffraction efficiency of acoustooptical Q-switched laser in a certain output pulse energy is studied. Through soluting the population inversion density , the relationship between a certain output pulse energy and cavity loss,the necessary minimum diffraction efficiency of Q-switch , the reflectivity of output mirror and so on,are acquired. The result can be used to design the diffraction efficiency of acoustooptical Q-switched laser..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1445 (2005)
An Novel Laser-Optically Pumped Vertical External Cavity Surface Emission Laser
, , , ... and |Show fewer author(s)
A novel laser-optically pumped vertical external cavity surface emitting laser was demonstrated.A diode laser was employed as a pump source.The gain structure of the semiconductor was quantum wells grown by MOCVD technology.By adjusting the cavity which was typically plane-concaved structure carefully,the laser was obtA novel laser-optically pumped vertical external cavity surface emitting laser was demonstrated.A diode laser was employed as a pump source.The gain structure of the semiconductor was quantum wells grown by MOCVD technology.By adjusting the cavity which was typically plane-concaved structure carefully,the laser was obtained at 1005 nm centre wavelength and the output power was 40 mW.The optical-optical efficiency was 2.7%..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1448 (2005)
A Method for Tracking Multiple Maneuvering Targets with Single Observer of IRSTS
, , and
A method for tracking multiple maneuvering targets with single observer of IRSTS is presented, It is set up by using the information of the bearing measurements and the sum of the infrared radiation power of the targets received by IRSTS and combining the IMM(Interacting Multiple Model) and the JPDA(Joint ProbabilisticA method for tracking multiple maneuvering targets with single observer of IRSTS is presented, It is set up by using the information of the bearing measurements and the sum of the infrared radiation power of the targets received by IRSTS and combining the IMM(Interacting Multiple Model) and the JPDA(Joint Probabilistic Data Association) algorithm.The performance of the algorithm is verified by two scenarios of multiple maneuvering targets tracking.The results show that at the beginning of the tracking, both the scenarios can be tracked effectively; when the targets fly at a forming columns, all the targets can be track effectively at the whole trajectory and the accuracy of the tracking is satisfied; when the targets fly crossly, the RMS position error changes large obviously and give a invalid track to the target at the distance at the end of the trajectory, but the near target can be tracked effectively at the whole trajectory..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1451 (2005)
Fabrication of Waveguides with Arbitrary Index Profiles in LiNbO3 : Fe Crystal by White Light Irradiation
, , , , and
On the basis of the theoretical analysis of the relations between the distributions of light-induced index changes and the intensity profiles of writing beams,a novel optical approach for fabricating waveguides with arbitrary index profiles is proposed. Waveguide structures with index profiles of an error function distOn the basis of the theoretical analysis of the relations between the distributions of light-induced index changes and the intensity profiles of writing beams,a novel optical approach for fabricating waveguides with arbitrary index profiles is proposed. Waveguide structures with index profiles of an error function distribution and a square law distribution are fabricated respectively employing writing beams with different intensity profiles generated by a white light beam reading out gray patterns from an electrically addressed spatial light modulator (SLM).Employing the interferometric technique,the light-induced index changes in the crystal sample are measured,which are well fitted by using the deduced analytic expressions of the index change distributions.Experimental results show that the method is feasible.High quality waveguide devices with arbitrary index profiles may be fabricated in various photorefractive media employing white light irradiations and spatial light modulators with high resolutions..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1456 (2005)
Reflected properties Analysis of Thin-film Waveguide-grating Filters
, , , and
Waveguide-grating filters with single-layer and triple-layer thin-film structure were designed,which were based on the theory that reflected sidebands depressed more by introducing antireflection structures of thin-film into waveguide-gratings.The purpose was to obtain narrow linewidth and high peak response in wide spWaveguide-grating filters with single-layer and triple-layer thin-film structure were designed,which were based on the theory that reflected sidebands depressed more by introducing antireflection structures of thin-film into waveguide-gratings.The purpose was to obtain narrow linewidth and high peak response in wide spectral range by using layers as few as possible.Rigorous coupled-wave theory was used in precise calculation on the possible structures of single-layer and triple-layer thin-film waveguide filters,and good reflected curves were obtained.Furthermore,a good triple-layer thin-film structure which was easy achieved in experiment in wide spectral range was also obtained..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1461 (2005)
The Gain Performance of a Double-clad Dye-doped Polymer Optical Fiber Amplifier
, and
Double-clad polymer optical fiber amplifiers (POFA) have lower dyes bleaching.A numerical model for characterizing double-clad dye-doped polymer optical fiber amplifiers is proposed. Based on rate equation and the pump power propagation equation in a double-clad dye-doped polymer fiber,the models take into account bothDouble-clad polymer optical fiber amplifiers (POFA) have lower dyes bleaching.A numerical model for characterizing double-clad dye-doped polymer optical fiber amplifiers is proposed. Based on rate equation and the pump power propagation equation in a double-clad dye-doped polymer fiber,the models take into account both the influences of the ternary state of dye molecule on rate equation and double-clad scheme on pump light absorption.The model is capable to predict amplifier gain,output spectrum and gain saturation when the POFA is in a steady state.The numerical simulation result shows the Double-clad POFA can achieve a gain of 39 dB when pumping power is 7 kW..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1466 (2005)
Measurement of Refractive Index of Polystyrene Beads by Using Mie Scattering Theory
, , , and
The present paper exploits a full Mie theory, in theory, to study the scattered pattern of parallel monochromatic light passing through the bead-water-aerosol cuvette. In experiment, the bead concentration was adjusted to make the transmission of the light through the cuvette to be about 70%, and the scattering patternThe present paper exploits a full Mie theory, in theory, to study the scattered pattern of parallel monochromatic light passing through the bead-water-aerosol cuvette. In experiment, the bead concentration was adjusted to make the transmission of the light through the cuvette to be about 70%, and the scattering pattern in far field was measured for the angular radius of its first dark ring. The measured angular radius value was compared with those computed theoretically for varying indices of refraction.The best comparison gave the value of the relative index of refraction with respect to that of the pure water. From the refractive index of water, a value of n = 1.6 of the refractive index for these plastic particles were inferred, thereby providing a key optical parameter for these Standard-Matter beads..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1473 (2005)
The Concept of the Beam Width and Comparison of Its Different Definitions
, , and
A comparative study of different definitions of the beam width was made. It was shown that there were different values of the beam width in accordance with different definitions. The propagation of the second-order-moment-based width obeyed the ABCD law,and the propagation curve of the entropy-based width was approximaA comparative study of different definitions of the beam width was made. It was shown that there were different values of the beam width in accordance with different definitions. The propagation of the second-order-moment-based width obeyed the ABCD law,and the propagation curve of the entropy-based width was approximately a hyperbola, but for the power-in the bucket-based width the ABCD law failed. There were nearly the same focal shifts of Cosh-Gaussian (ChG) beams for the second-order-moment-based width and entropy-based width, whereas it was not the case for the power-in the bucket-based width..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1476 (2005)
Theoretical Calculation of the Third Order Nonlinear Optical Properties in Strongly Coupled Exciton-Phonon Systems
, , , , and
The third order nonlinear optical properties in strongly coupled exciton-phonon systems are investigated theoretically. It is shown that as the signal field frequency detuning from the exciton frequency is equal to the optical phonon frequency the nonlinear optical absorptions and Kerr coefficient are enhanced significThe third order nonlinear optical properties in strongly coupled exciton-phonon systems are investigated theoretically. It is shown that as the signal field frequency detuning from the exciton frequency is equal to the optical phonon frequency the nonlinear optical absorptions and Kerr coefficient are enhanced significantly. The results also demonstrate that the phase-space filling effect has an evident impact on the nonlinear optical properties of the system..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1480 (2005)
The Influence of Solvent on Optical Performances of Photochromic Materials-ethyl Red
, , , ... and |Show fewer author(s)
The influence of solvent effect on optical performances of photochromic material ethyl red has been studied.The solvent induced changes of absorption spectra of ethyl red solutions are measured. The nonlinear optical properties of different solution layers of ethyl red and their optical limiting are measured by Z-scan.The influence of solvent effect on optical performances of photochromic material ethyl red has been studied.The solvent induced changes of absorption spectra of ethyl red solutions are measured. The nonlinear optical properties of different solution layers of ethyl red and their optical limiting are measured by Z-scan. The relations between Δα and properties of solvents are discussed.It is found that with the increasing of polarity of solvents, the absorption spectra are blue shift, so the application “window” of the nonlinear material can be changed by choosing different solvents.The experimental results show that the nonlinear refraction of dye irradiated by cw laser is mainly caused by the thermal effect,and the influence of thermal character of solvents to n_2 is relatively great.Furthermore,the nonlinear absorption in Z-scan result is saturable absorption,which mainly caused by polarities of solvents.As far as optical limiting effect is also induced chiefly by thermal effect,its dynamic range of the optical.......
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1485 (2005)
Study on Third Optical Nonlinearity of Porous Silicon/DR1 Composite Films
, , and
The porous silicon and push-pull azobenzene compounds disperse red 1 (DR1) composite films have been prepared by physical adsorption method,and the third optical nonlinearities of samples were studied by single beam technique(Z-scan ) in this paper.The nonlinear absorption and nonlinear refractive index of porous silicThe porous silicon and push-pull azobenzene compounds disperse red 1 (DR1) composite films have been prepared by physical adsorption method,and the third optical nonlinearities of samples were studied by single beam technique(Z-scan ) in this paper.The nonlinear absorption and nonlinear refractive index of porous silicon/DR1 composite films at 1064nm have been measured respectively.The experiment results show that optical nonlinearity in porous silicon/DR1 composite films is enhanced obviously compared with porous silicon..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1490 (2005)
Experimental Study on Young's Modulus Measurement of Flexible Solid Fuel by Optical Fiber Strain Sensor
, , , and
Young′s modulus is a key characteristic of material, which can be got by strain and load of material. Because the flexible solid fuel is soft and incendive, traditional measurement method using strain slice is unsuitable. So a new method should be put forward. In this paper, optic fiber F-P strain sensor is stick on thYoung′s modulus is a key characteristic of material, which can be got by strain and load of material. Because the flexible solid fuel is soft and incendive, traditional measurement method using strain slice is unsuitable. So a new method should be put forward. In this paper, optic fiber F-P strain sensor is stick on the surface of the flexible solid fuel to measure the strain of flexible solid fuel. And the weights supply load. Theory analysis is carried on. Experiments demonstrate that the measurement standard deviation is about 23.04 MPa and receivable, and the measurement method using optic fiber F-P strain sensor is agreeable..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1494 (2005)
Brillouin Scattering Distributed Optical Fiber Sensors Series Connected by Wavelength Division Multiplexing
, , and
For a given resolution, single Brillouin scattering distributed optical-fiber sensor can only reach a definite sensing length, and in some applications, sensing and communication should be run in a single fiber. Wavelength division multiplexing and optical heterodyne detecting were used to series connect Brillouin scatFor a given resolution, single Brillouin scattering distributed optical-fiber sensor can only reach a definite sensing length, and in some applications, sensing and communication should be run in a single fiber. Wavelength division multiplexing and optical heterodyne detecting were used to series connect Brillouin scattering distributed optical-fiber sensors. Wavelength division multiplexing was adopted to isolate the sensing light and the communication light. The optical heterodyne detecting was used to vary the spectrum of sensing signal from the communication signal. The series connecting between two Brillouin scattering distributed optical-fiber sensors was achieved, the sensing length of single sensor was 25 km, and the sensing length of two series connecting sensors was 50 km. The experimental results show that the configuration is feasible..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1497 (2005)
Measurement of the 3-D Thermal Expansion Coefficients of Material Used by a FBG During the Large-scale Temperature Between Negative 50℃ and Positive 150℃
, , , ... and |Show fewer author(s)
In order to measure materials of 3-D hermal expansion coefficient under the condition of the bad environment,a novel method was proposed in this paper.The thermal expansion coefficience of the new material was measured by using a Fiber Bragg Grating sensor.The results of experiment indicate that this method could be fuIn order to measure materials of 3-D hermal expansion coefficient under the condition of the bad environment,a novel method was proposed in this paper.The thermal expansion coefficience of the new material was measured by using a Fiber Bragg Grating sensor.The results of experiment indicate that this method could be full of credibility in examining the thermal expansion coefficient under the condition of the bad environment,at of the large-scale temperature of bellowing to negative 50℃ and highing to 150℃ the FBG could also be in a good working condition.The text gave the theory correspondence and the results of experiment..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1501 (2005)
Experimental Reseach of the Parallel Multiplexing of Fabry-Perot Strain Sensor in the Fourier Demodulation
, , , ... and |Show fewer author(s)
The Fourier demodulation of the output signal of the Fabry-Perot strain sensor was analyzed.The principle of the parallel multiplexing according to Fourier demodulation was introduced particularly.Based on this principle,many experiments have been done,of which three experiments have been analyzed emphatically.The expeThe Fourier demodulation of the output signal of the Fabry-Perot strain sensor was analyzed.The principle of the parallel multiplexing according to Fourier demodulation was introduced particularly.Based on this principle,many experiments have been done,of which three experiments have been analyzed emphatically.The experimental results indicate that this demodulation method is valid and practical..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1506 (2005)
The Application of Spectral Unmixing Technology for Lunar Regolith
, , and
Spectral unmixing technology has been developed to solve mixing pixel problem, the linear mixing model is more successful to this day. But when applied to the lunar regolith, it would have two limitations: the nonlinerity of intimate mixture and the error caused by the lack of endmember spectra. As to the former, simplSpectral unmixing technology has been developed to solve mixing pixel problem, the linear mixing model is more successful to this day. But when applied to the lunar regolith, it would have two limitations: the nonlinerity of intimate mixture and the error caused by the lack of endmember spectra. As to the former, simpled multiple scattering model based on Hapke's theory is developed to improve the linearity of intimate mixture and reduce computational complexity; as to the latter, Modified Linear Mixing Model (MLMM) is advanced to compensate for the error in endmember spectra. The motheds are test by the simulated lunar soils' spectra data gained from the Relab, the experimental result display their good performances..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1510 (2005)
Spectral Multicomponent Analysis Based on Wavelet Transform and Support Vector Machine
, , , , and
This paper took spectral signal according with Lambert-beer law as object,and introduced basic method of denoise with wavelet transform,and researched and established model of spectral multicomponent analysis based on support vector machine.Then computer simulation method gave an example to explain in the end,the exampThis paper took spectral signal according with Lambert-beer law as object,and introduced basic method of denoise with wavelet transform,and researched and established model of spectral multicomponent analysis based on support vector machine.Then computer simulation method gave an example to explain in the end,the example indicated that the method based on support vector machine can preferably solve the question of nonlinearity, small-sample in the spectral multicomponent analysis..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1514 (2005)
Analysis and Revision on Spectra Aliasing of Hadamard Transform Spectral Imager
, , and
The principle and instrument structure of Hadamard transform spectral imager is described, and spectra aliasing caused by Hadamard encoding mask is investigated. Spectra aliasing formula is obtained in theory and the method of spectra revision is proposed.Simulation results show that this method is simple and effectiveThe principle and instrument structure of Hadamard transform spectral imager is described, and spectra aliasing caused by Hadamard encoding mask is investigated. Spectra aliasing formula is obtained in theory and the method of spectra revision is proposed.Simulation results show that this method is simple and effective. The resolution of spectral images revised depends on space component corresponding to the code which is deviated from optic axis most..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1518 (2005)
Photoluminescence Investigation of Porous Anodic Alumina Films
, , , ... and |Show fewer author(s)
Porous anodic aluminum oxide films with nanometer porosity have been fabricated by electrochemical method in the aqueous solution of oxalic acid. Regular porosity in about 38 nanometer size was observed using atomic force microscopy. Excitation and Emission spectrum were obtained by using F-4500 fluorometer.Compared wiPorous anodic aluminum oxide films with nanometer porosity have been fabricated by electrochemical method in the aqueous solution of oxalic acid. Regular porosity in about 38 nanometer size was observed using atomic force microscopy. Excitation and Emission spectrum were obtained by using F-4500 fluorometer.Compared with aluminum of not oxidize , the former has a broad peak band at about 280 nm~340 nm and a second peak at 253.8 nm in excitation spectrum, including a broad peak band at 417.4 nm in emission spectrum, while the latter without any obvious peak in either excitation or emission spectrum. Blue emission was obtained when sample was excited using 248 nm and 355 nm laser. The photoluminescence was attributed to the local structure caused by unbalance of Al and O as well as involvement of electrolyte during oxidization process, at the same time, quantum localization effect affected its optical properties..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1522 (2005)
Influence of Inhomogeneities on the Optic Characteristics of Single Coatings
, , , , and
Influence of different inhomogeneities on the spectral characteristics of dielectric single layers was discussed.Comparing with homogeneous coatings,it is found:the maximum of the film with positive change decreased, and with negative change increased ; the minimum of the film changed little when the inhomogeneity was Influence of different inhomogeneities on the spectral characteristics of dielectric single layers was discussed.Comparing with homogeneous coatings,it is found:the maximum of the film with positive change decreased, and with negative change increased ; the minimum of the film changed little when the inhomogeneity was small comparing with homogeneity film. Through the comparison of the film in theoretic and experimental,there are transitional layers between substrate and coatings, and the refractive index lies between them..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1526 (2005)
Preparation and Optical Properties of Porous Anodic Alumina Film
Nanostructural porous alumina films with two dimension ordered arrangements are prepared by the anodic oxidation.Influence of the conditions for the formation of the pores on the porous structure with ordered nanopore arrays,the diameter of the pores and the thickness of the films are discussed.An investigation is madeNanostructural porous alumina films with two dimension ordered arrangements are prepared by the anodic oxidation.Influence of the conditions for the formation of the pores on the porous structure with ordered nanopore arrays,the diameter of the pores and the thickness of the films are discussed.An investigation is made on the optical transmittance,optical absorption and photoluminescence of the porous anodic alumina film.It is found that the transmittance spectra and absorption spectra of porous anodic alumina film abruptly curve at wavelength of 360 nm,the optical transmittance increases at wavelength more than 360 nm,the optical absorption increases at wavelength less than 360 nm.The photoluminescence intensity and peak position of the porous anodic alumina film depend strongly on the excitation wavelength,there is a wide blue photoluminescence band in the wavelength range of 340~600 nm..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1530 (2005)
Analysis of Influences of Coaxial Holographic Nonlinear Recording for Particles Field on Image Reconstruction by Using the Threshold Value Function
, , , ... and |Show fewer author(s)
The influence on image reconstruction of the coaxial holographic nonlinear recording for particles field was analyzed by using the threshold value function. In theory, the simulation model was built, in which the reconstructions of different shapes particles were recorded in the nonlinear segment of D-LogE. The effect The influence on image reconstruction of the coaxial holographic nonlinear recording for particles field was analyzed by using the threshold value function. In theory, the simulation model was built, in which the reconstructions of different shapes particles were recorded in the nonlinear segment of D-LogE. The effect of edge shearing appeared in the reconstruction. The simulation result and the experimental result are in good agreement. The result can develop the theory of the in-line holography. The effect of edge shearing not only offer the optic method for the image manipulation in the particle in-line holography but also shorten the time of image..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1534 (2005)
A New Method for Computer-generated Rain-bow Hologram
, , , , and
A new method to make computer generated rainbow hologram using look-table is proposed.According to the relation of object point position with its line-element hologram,an object light distribution data table is established.This data table contains the line-element hologram′s object light digital distribution of all posA new method to make computer generated rainbow hologram using look-table is proposed.According to the relation of object point position with its line-element hologram,an object light distribution data table is established.This data table contains the line-element hologram′s object light digital distribution of all possible object points. For any actual objects,its all sample points′ light distribution can be obtained by looking the data table.Adding all the sample points′ light distribution,the actual object′s light distribution can be got.Computer-generated rain-bow hologram can be made by calculating interference fringe of the object light distribution and of reference light.This method well utilizes the characters of line-element hologram to increase computing speed..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1537 (2005)
Measuring Nanoscale Motions of Microdevices Using a Mirau Interferometer
, , , ... and |Show fewer author(s)
A Mirau microscopic interferometric system for measuring three-dimensional motions of microelectromechanical systems (MEMS) with nanometer resolution is demonstrated.The system utilizes a commercial Mirau microscopic interferometer,which mounts directly on a light microscope.The system was used for full three dimensionA Mirau microscopic interferometric system for measuring three-dimensional motions of microelectromechanical systems (MEMS) with nanometer resolution is demonstrated.The system utilizes a commercial Mirau microscopic interferometer,which mounts directly on a light microscope.The system was used for full three dimensional motion measurement of a surface micromachined lateral resonator.In-plane motions were determined from stop-action bright field images taken at the best plane of focus.Out-of-plane motions were determined from stroboscopic interferograms obtained at eight different positions of the objective nanopositioner.Experimental results demonstrate nanometer resolution for both in-plane and out-of plane motions..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1542 (2005)
Optical Coupled-dipole Model for Scanning Near-field Optical Microscopy
, , and
An optical coupled-dipole model was proposed in order to study the coupling between the probe tip and the rough sample in SNOM. In this model both the optical probe tip and the sample protrusions were represented by optical polarizable dipole spheres. The induced polarization effects on the sample surface can be replacAn optical coupled-dipole model was proposed in order to study the coupling between the probe tip and the rough sample in SNOM. In this model both the optical probe tip and the sample protrusions were represented by optical polarizable dipole spheres. The induced polarization effects on the sample surface can be replaced by the image dipoles in the context of quasi-static electromagnetic field approximation. Applying the radiation theory of the dipole,a set of self-consistent equations have been established to describe the field distribution at the sites of the probe tip and the sample protrusions. This method permits us to analyze the physical mechanisms of the interaction between the probe tip and the rough sample surface in SNOM intuitively. On the basis of this approach,the characteristic of the near-field imaging and the localized optical resonance of the metallic sample were discussed. The calculating result indicates that its near-field images were directly related to the incident light frequency,.......
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1546 (2005)
Frequency-varying 3-D Digital Imaging Based on Dual Acousto-optic Deflectors
, , , ... and |Show fewer author(s)
A three-dimensional profilometry based on a dual-acousto-optic fringe projection is presented. The fringe projector is able to generate a time-series, frequency-varying fringe patterns by using the acousto-optic interaction effect. The system is qualified for video-rate 3-D profilometry of arbitrary shape objects. The A three-dimensional profilometry based on a dual-acousto-optic fringe projection is presented. The fringe projector is able to generate a time-series, frequency-varying fringe patterns by using the acousto-optic interaction effect. The system is qualified for video-rate 3-D profilometry of arbitrary shape objects. The AO technique for producing interference patterns provides significant benefits, such as high precision, full field and dynamic programmable ability. Experimental results of a step-like surface are also carried out to demonstrate the effectiveness of our approach..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1550 (2005)
The Contributions of Each Refractive Surface of the Human Model Eye to the Aberrations
, , , and
The theory of computing the contributions of each refractive surface of the optical system to total aberrations was applied to the human eye model for the first time. To compute the contributions of each refractive surface and the variation of the aberrations after each surface, a ray tracing program has been written iThe theory of computing the contributions of each refractive surface of the optical system to total aberrations was applied to the human eye model for the first time. To compute the contributions of each refractive surface and the variation of the aberrations after each surface, a ray tracing program has been written in C language. For the first time the contributions of each refractive surface to the coma were computed. And the coma aberrations caused by cornea and that caused by lens can be compensated for each other. Cornea anterior surface contributes most to the eye aberrations and the posterior surface of the lens played the second role which can give good information to the design of artificial crystalline lens..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1554 (2005)
Imaging and Image Reconstruction of Optical Sparse-Aperture Systems
, , , ... and |Show fewer author(s)
Optical sparse-aperture system can be designed to obtain high resolution in astronomical object imaging. It is a particular array synthesized by several small filled imaging systems. A diffraction-limited incoherent imaging model is proposed for sparse-aperture systems. Under the premise that the noise of sparse-apertuOptical sparse-aperture system can be designed to obtain high resolution in astronomical object imaging. It is a particular array synthesized by several small filled imaging systems. A diffraction-limited incoherent imaging model is proposed for sparse-aperture systems. Under the premise that the noise of sparse-aperture system can be regarded as ergodic random noise, and is uncorrelated to the object, then an optimum image reconstruction filter is given for sparse-aperture system in a sense of mean square errors. Finally, computer simulations of imaging and image reconstruction of a specific sparse-aperture system are performed by using the model and the filter. These numerical experiments indicate that optical sparse-aperture systems can achieve almost the same resolution and image quality as an equivalent filled system..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1557 (2005)
Theory Study on Axial Magnetic Field Acting on Fiber-Optic Depolarized Gyro
, , , and
The axial magnetic sensitivity of fiber-optic depolarized gyro is studied through using Jones Matrix.Based on monochromatic light,the principle of resulting in nonreciprocal phase error that results from axial magnetic is analyzed,and the theory derivation about the actual nonreciprocal phase error is introduced.The emThe axial magnetic sensitivity of fiber-optic depolarized gyro is studied through using Jones Matrix.Based on monochromatic light,the principle of resulting in nonreciprocal phase error that results from axial magnetic is analyzed,and the theory derivation about the actual nonreciprocal phase error is introduced.The emulation result,analysis result and the experiment result are given.And the main method to reduce the Faraday nonreciprocal phase error resulted from the axial magnetic field is put forward,too.The method is that the two depolarizers′ 45° error sum(θ_3+θ_4) should tend to 0..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1561 (2005)
Measuring Modulation Transfer Function with Mask for Imaging Sensor
, , and
Modulation transfer function is a powerful tool to evaluate the imaging performance of optics system.In order to expediently evaluate imaging quality of imaging sensor,a new method using sine mask to measure modulation transfer function is presented,which is based on the interferential fringe measurement method.The sinModulation transfer function is a powerful tool to evaluate the imaging performance of optics system.In order to expediently evaluate imaging quality of imaging sensor,a new method using sine mask to measure modulation transfer function is presented,which is based on the interferential fringe measurement method.The sine pattern generated by sine mask is directly projected on the imaging sensor,and the sine image is achieved.Then the modulation transfer function can be calculated.The approximate experiment is carried out,making use of rectangular grating which spatial frequency is 25 l/mm.The approximate modulation transfer coefficient is obtained with the corresponding data processing technology.The result indicates that such method is agreeable..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1565 (2005)
Cladding Mode's Characteristic and Its Affects on Transmission Spectrum of Long Period Fiber Gratings
, , , , and
Based on the coupling-mode theory, the changing relations of the effective refractive index and its AC/ DC coupling coefficient in different order of cladding modes in long period gratings, versus the varying of wavelength and the order, are numerically calculated and analyzed. It is revealed that the effective refractBased on the coupling-mode theory, the changing relations of the effective refractive index and its AC/ DC coupling coefficient in different order of cladding modes in long period gratings, versus the varying of wavelength and the order, are numerically calculated and analyzed. It is revealed that the effective refractive index and the DC coupling coefficient, as well as the AC coupling coefficient of odd order modes, will be decreased with the increase in wavelengths. It is also shown that changing rates of the effective refractive index and the ac coupling coefficient of odd order modes corresponding to higher orders are bigger than that corresponding to lower orders. The effects of DC coupling coefficient on the resonant wavelength peak are further analyzed, and the reason that the difference between adjacent resonant wavelength peaks is gradually getting bigger with wavelength increase is finally revealed..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1569 (2005)
Investigation on Characteristic of PMMA Optical Fiber Under Irradiation
The physical and chemical characteristics change of polymer under irradiation environment was analyzed. The irradiation damage and recovery property for polymethylmethacrylate (PMMA) optical fiber under γ-ray irradiation were researched experimentally. The visible light transmission spectrum and recovery property of thThe physical and chemical characteristics change of polymer under irradiation environment was analyzed. The irradiation damage and recovery property for polymethylmethacrylate (PMMA) optical fiber under γ-ray irradiation were researched experimentally. The visible light transmission spectrum and recovery property of the POF under different irradiation dose were measured. Under different irradiation dose the light transmission rate was reduced by different ratio. The measured spectrum indicated that the POF irradiation damage and recovery were dependent on wavelength, and the visible light transmission rate of the POF at the range of 400 nm to 550 nm comparing 600 nm to 800 nm, decreased seriously under the irradiation dose exceeded 5 kGy. But under lower dose below 1 kGy, the transmission rate decreased identical at the whole visible light range..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1573 (2005)
Effect of Strain or Temperature on Reflective Spectra Character of λ/4 Phase-shifted Grating
, , , and
Using the matrix approach and Mathematica calculation,the main reflective spectra character of λ/4 phase-shifted fiber grating was analysed with the conditions such as strain and temperatures changed and draw some disciplinary conclusions.These theoretical results have important instruction for the fabrication of phaseUsing the matrix approach and Mathematica calculation,the main reflective spectra character of λ/4 phase-shifted fiber grating was analysed with the conditions such as strain and temperatures changed and draw some disciplinary conclusions.These theoretical results have important instruction for the fabrication of phase-shifted grating and its application in sensors..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1577 (2005)
Dynamic Analysis for Optical Tweezers Upon Cells as Microsphere Model
, , and
A dynamic method was used to solve the mean-square displacement of a trapping microsphere which simulates a common biological cell. Results shows that the cell obeys Boltzmann distribution,and two methods deduced from the solutions fit directly for cells force calibration; the cell’s motional displacement amplitude is A dynamic method was used to solve the mean-square displacement of a trapping microsphere which simulates a common biological cell. Results shows that the cell obeys Boltzmann distribution,and two methods deduced from the solutions fit directly for cells force calibration; the cell’s motional displacement amplitude is in the order of nanometer,and the spatial resolution of the calibration system is about nanometer. Results are agree with the experiments report..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1582 (2005)
A Study of 70 mm High Speed Photography Camera
, , , and
A set of 70mm high speed photography camera(HSPC) system has been developed ,which is such an instrument that it can record the 3D flying position and space parameter of object such as laser-guided bomb,rocket and guided missile. The main constitutes and the principle is introduced and the design of camera is describedA set of 70mm high speed photography camera(HSPC) system has been developed ,which is such an instrument that it can record the 3D flying position and space parameter of object such as laser-guided bomb,rocket and guided missile. The main constitutes and the principle is introduced and the design of camera is described in detail. Because 70 mm HSPC System has successful application, it can offers a few ideas to the design of other HSPC..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1586 (2005)
Analysis of the MTF of the TDI-CCD Camera
, , and
TDI-CCD Subpixel dynamic imaging technology was a valid novel approach for meeting the requirements of high-resolution and lightweight of remote sensing cameras. Because of its special work method, the affect of velocity mismatch and misalignment was unavoidable.Through analyzing the effect on MTF, the result shows thaTDI-CCD Subpixel dynamic imaging technology was a valid novel approach for meeting the requirements of high-resolution and lightweight of remote sensing cameras. Because of its special work method, the affect of velocity mismatch and misalignment was unavoidable.Through analyzing the effect on MTF, the result shows that it is very important to improve quality of imaging through improving the synchronous accuracy and reducing the drift angle..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1590 (2005)
Improved MPEG-4 VTC BQ Mode coding Algorithm
, and
According to the coding process of MPEG-4 VCT,coding-decoding frame of VTC consistent with standard of MPEG-4 is presented. The problem of scalable MPEG-4 VCT BQ image coding is investigated from the viewpoint of consistency of zerotree symbol with the objective image of bit-stream layer. An improved PEZW algorithm, SPAccording to the coding process of MPEG-4 VCT,coding-decoding frame of VTC consistent with standard of MPEG-4 is presented. The problem of scalable MPEG-4 VCT BQ image coding is investigated from the viewpoint of consistency of zerotree symbol with the objective image of bit-stream layer. An improved PEZW algorithm, SP-PEZW is presented. The experiment of the color Lena image is researched applying to SP-PEZW. Experiment results show that PEZW algorithm comparing with the bitrate of low resolution bitstream layers of SP-PEZW algorithm is lower, while bitrate of the highest resolution bitstream layer is the same, and image of the highest resolution spatial layer which is decoded at the special bitrate is better..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1593 (2005)
A Novel Approach to the Detection of Shot Boundary
, , and
For the detection of shot boundary in a video sequence,the selection of a proper threshold for computing discontinuity values is an important and difficult problem.A formula for calculating discontinuity values is defined,then a new Gaussian model based technique is proposed,which needs not setting low boundary threshoFor the detection of shot boundary in a video sequence,the selection of a proper threshold for computing discontinuity values is an important and difficult problem.A formula for calculating discontinuity values is defined,then a new Gaussian model based technique is proposed,which needs not setting low boundary threshold. It is a kind of improvement of twin-comparison method. Primary experimental results demonstrate that the proposed method enables to locate boundaries of gradual transitions and cuts exactly and quickly..
Acta Photonica Sinica
- Publication Date: Oct. 31, 2005
- Vol. 34, Issue 10, 1597 (2005)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20