2005 Vol. 26, No. 2
Display Method:
2005, 26(2): 1-6.
Abstract:
The novel highenergy laser weapons have been studies and developed for more than forty years. The first generation highenergy laser weapons mainly employ chemical CW lasers with excellent engineering scaling and good beam quailty. The second generation highenergy laser weapons mainly use solidstate lasers with shorter wavelength and different working mode to reach the lethal and damage effect with minimal output energy. With the development and deployment of highenergy laser weapon, it is very necessary for optical metrology and measurement of the highenergy laser weapon, it is very necessary for optical metrology and measurement of the highenergy laser parameters (such as energy/power, laser waveform, beam quality, near field and field intensity distributions, beam pointing stability, spectrum and polarization feature) to be done. In this paper, the present state and development trend for the novel highenergy laser weapons are reviewed. It is a great challenge for optical metrology test of the highenergy laser to meet the requirement of the research and development of the highenergy laser to meet the requirement of the research and development of highenergy laser weapon systems.
The novel highenergy laser weapons have been studies and developed for more than forty years. The first generation highenergy laser weapons mainly employ chemical CW lasers with excellent engineering scaling and good beam quailty. The second generation highenergy laser weapons mainly use solidstate lasers with shorter wavelength and different working mode to reach the lethal and damage effect with minimal output energy. With the development and deployment of highenergy laser weapon, it is very necessary for optical metrology and measurement of the highenergy laser weapon, it is very necessary for optical metrology and measurement of the highenergy laser parameters (such as energy/power, laser waveform, beam quality, near field and field intensity distributions, beam pointing stability, spectrum and polarization feature) to be done. In this paper, the present state and development trend for the novel highenergy laser weapons are reviewed. It is a great challenge for optical metrology test of the highenergy laser to meet the requirement of the research and development of the highenergy laser to meet the requirement of the research and development of highenergy laser weapon systems.
2005, 26(2): 7-9.
Abstract:
Some types of novel absorbers for solidstate laser passive Qswitching developed in recent years are introduced, such as Cr4+ doped series,Cr,Nd∶YAG selfQswitching laser crystal,absorbers for passive Qswitching eyesafe lasers, GaAs absorber, semiconductor saturable absorption mirror.The principle, application and exploratory development of semiconductor saturable absorption mirrors for passive Qswitching of solidstate lasers and fiber lasers are emphasized.
Some types of novel absorbers for solidstate laser passive Qswitching developed in recent years are introduced, such as Cr4+ doped series,Cr,Nd∶YAG selfQswitching laser crystal,absorbers for passive Qswitching eyesafe lasers, GaAs absorber, semiconductor saturable absorption mirror.The principle, application and exploratory development of semiconductor saturable absorption mirrors for passive Qswitching of solidstate lasers and fiber lasers are emphasized.
2005, 26(2): 10-14.
Abstract:
The relation between parameters (including dynamic range, uniformity of diffraction efficiency and Bragg selectivity), Which will affect the performance of highdensity volume holographic storage, and geometric conffiguration is discussed. The importance of the three parameters of balanced consideration in the beampath configuration is emphasized. According to the analysis of LiNbO3 crystal with the principle of the balance, it is pointed out that the 90° writing beampath with Olight coupling is the best geometic configuration.
The relation between parameters (including dynamic range, uniformity of diffraction efficiency and Bragg selectivity), Which will affect the performance of highdensity volume holographic storage, and geometric conffiguration is discussed. The importance of the three parameters of balanced consideration in the beampath configuration is emphasized. According to the analysis of LiNbO3 crystal with the principle of the balance, it is pointed out that the 90° writing beampath with Olight coupling is the best geometic configuration.
2005, 26(2): 15-17.
Abstract:
The technology of OCDMA has many advantages in access network. The design of great capability address codes is the precondition to practicability of this technique. In this paper, on the basis of constructing the 2D prime code, we put forward a kind of space/frequency/time 3D code for OCDMA system. It's based on prime sequence arithmetic. The results of the theory analysis and methematic computation show that, comparing with the 2D code, this 3D code has larger capacity, lower BER, higher bandwidth efficiency and better performance.
The technology of OCDMA has many advantages in access network. The design of great capability address codes is the precondition to practicability of this technique. In this paper, on the basis of constructing the 2D prime code, we put forward a kind of space/frequency/time 3D code for OCDMA system. It's based on prime sequence arithmetic. The results of the theory analysis and methematic computation show that, comparing with the 2D code, this 3D code has larger capacity, lower BER, higher bandwidth efficiency and better performance.
2005, 26(2): 18-20.
Abstract:
At the industrial insite conditions, the small size can't be quickly and accurately measured by the traditional measurement way. Based on the need for small size measurement in industry, a kind of photoelectric measuring apparatus to clearance is designed in this paper. We use the linear array CCD (Charge Coupled Device) as a photoelectric sensor and singlechip computer as a main control unit to do the noncontact and online measurement of clearance between the gear and highfrequency quenching inductor, and get a good measurement result. Therefor, the apparatus can monitor the production status and improve the working efficiency. This project is suitable for the application of low cost and high precision measurement.
At the industrial insite conditions, the small size can't be quickly and accurately measured by the traditional measurement way. Based on the need for small size measurement in industry, a kind of photoelectric measuring apparatus to clearance is designed in this paper. We use the linear array CCD (Charge Coupled Device) as a photoelectric sensor and singlechip computer as a main control unit to do the noncontact and online measurement of clearance between the gear and highfrequency quenching inductor, and get a good measurement result. Therefor, the apparatus can monitor the production status and improve the working efficiency. This project is suitable for the application of low cost and high precision measurement.
2005, 26(2): 21-23.
Abstract:
The article summarized the status quo and trend of the lowlightlevel image intenssifier in the recent years. Now,the development of lowlightlevel devices will be in the direction towards IV generation proximity focus image intensifier. The breakthrough of its technology at two points has made as follows:(1) the use of uncoated MCP;(2) the use of fusion technology of IR thermal imaging and lowlightlevel night vision for the photocathode. Night vision instruments are advancing towards smallsized, portable and cheap oneman helmetmounted displays and monocular/binocular night visions,and light arm sights.The life of LLL device is the key problem which we have to solve for applications.
The article summarized the status quo and trend of the lowlightlevel image intenssifier in the recent years. Now,the development of lowlightlevel devices will be in the direction towards IV generation proximity focus image intensifier. The breakthrough of its technology at two points has made as follows:(1) the use of uncoated MCP;(2) the use of fusion technology of IR thermal imaging and lowlightlevel night vision for the photocathode. Night vision instruments are advancing towards smallsized, portable and cheap oneman helmetmounted displays and monocular/binocular night visions,and light arm sights.The life of LLL device is the key problem which we have to solve for applications.
2005, 26(2): 24-26.
Abstract:
The independent twocell system was numerically simulated by the theoretical model of the transient stimulated Brillouin scattering. The depleted pump energy convertion efficiency versus pump power density is given. The experiment shows that the theoretical calculation is coincident with the experiment result.
The independent twocell system was numerically simulated by the theoretical model of the transient stimulated Brillouin scattering. The depleted pump energy convertion efficiency versus pump power density is given. The experiment shows that the theoretical calculation is coincident with the experiment result.
2005, 26(2): 27-30.
Abstract:
There are two types of laser scanning display, vector scanning and grating scanning. A comparison between the two scanning modes in the aspects of principles, application and prospects for development is made.The paper studies the principle of homochromous beam grating scanning.With reference to traditional TV,relations of the grating parameters, expressions of the brightness and modulation parameters are deduced. At the same time, these parameters are discussed.
There are two types of laser scanning display, vector scanning and grating scanning. A comparison between the two scanning modes in the aspects of principles, application and prospects for development is made.The paper studies the principle of homochromous beam grating scanning.With reference to traditional TV,relations of the grating parameters, expressions of the brightness and modulation parameters are deduced. At the same time, these parameters are discussed.
2005, 26(2): 31-33.
Abstract:
Based on Mie theory, the scattering figure and extinction curve of spherical particles with different sizes are presented. The scattering figure of a spherical particle shows that the scattering angle becomes narrow as the size of a partical increases gradually. From these extinction curves, we can see as the size of particles increases, the extinction efficiency factor tends to 2. Finally, the variation of polarization degree of scattering laser with particle size and scattering angle. Theses figures about polarization degrees versus the size of particles show taht as the size of the partcle increases, the peak of polarization degree extends forward, but the polarization degree decreases.
Based on Mie theory, the scattering figure and extinction curve of spherical particles with different sizes are presented. The scattering figure of a spherical particle shows that the scattering angle becomes narrow as the size of a partical increases gradually. From these extinction curves, we can see as the size of particles increases, the extinction efficiency factor tends to 2. Finally, the variation of polarization degree of scattering laser with particle size and scattering angle. Theses figures about polarization degrees versus the size of particles show taht as the size of the partcle increases, the peak of polarization degree extends forward, but the polarization degree decreases.
2005, 26(2): 34-36.
Abstract:
The nonprobe nearfield optical microscope is introduced in this paper, and the processing method and realization of the images are discussed. Based on the theory of Hadamard Transform imaging, the nonprobe nearfield optical microscope, which replaces the fiber probe with the nanometer multiaperture encoding mask, has a high optical signaltonoise ratio. The research shows that the nonprobe nearfield optical microscope can detect the evanescent nearfield wave effectively and the image with a superdiffraction limiting resolution can be obtained.All this will provide a new method for the research of the nearfield optics.
The nonprobe nearfield optical microscope is introduced in this paper, and the processing method and realization of the images are discussed. Based on the theory of Hadamard Transform imaging, the nonprobe nearfield optical microscope, which replaces the fiber probe with the nanometer multiaperture encoding mask, has a high optical signaltonoise ratio. The research shows that the nonprobe nearfield optical microscope can detect the evanescent nearfield wave effectively and the image with a superdiffraction limiting resolution can be obtained.All this will provide a new method for the research of the nearfield optics.
2005, 26(2): 37-39.
Abstract:
The principle of displaying a video character is that a character dot matrix signal is superimposed upon an original video signal. The key data and working state can be strikingly displayed on the monitor by superimposing some characters upon a video picture. Therefore, the technology of video character display is widely used. In this paper, a method of video character display , which uses CPLD along with a single chip microcomputer to realize the function of video character display and to show the realtime characters required to be viewed on the monitor,is presented. The experiments indicates that the circuit designed with this method is characterized by the stable performance and easy maintenance.
The principle of displaying a video character is that a character dot matrix signal is superimposed upon an original video signal. The key data and working state can be strikingly displayed on the monitor by superimposing some characters upon a video picture. Therefore, the technology of video character display is widely used. In this paper, a method of video character display , which uses CPLD along with a single chip microcomputer to realize the function of video character display and to show the realtime characters required to be viewed on the monitor,is presented. The experiments indicates that the circuit designed with this method is characterized by the stable performance and easy maintenance.
2005, 26(2): 40-42.
Abstract:
MachZehnder interferometer is suitable for studing the density change of gas. The variation of refractive index makes the beams getting through gas have different optical paths. Therefore, the density of gas can been acquired by changing the interference arm to affect interference fringe patterns. In real measurement,the fringe patterns generated by MachZehnder interferometer are collected by frame frabber and CCD, then the fringe spaces are processed by a computer to get the gas density change. This paper is base on light interference theory, analyses the property of MachZehnder fringe patterns and establish a math model. According to the math model, an arithmetic was designed to deal with MachZehnder interference fringe patterns. The arithmetic includes image preprocess(i.e. noise extraction of image)，gray image binarization and fringe pattern sharpening.
MachZehnder interferometer is suitable for studing the density change of gas. The variation of refractive index makes the beams getting through gas have different optical paths. Therefore, the density of gas can been acquired by changing the interference arm to affect interference fringe patterns. In real measurement,the fringe patterns generated by MachZehnder interferometer are collected by frame frabber and CCD, then the fringe spaces are processed by a computer to get the gas density change. This paper is base on light interference theory, analyses the property of MachZehnder fringe patterns and establish a math model. According to the math model, an arithmetic was designed to deal with MachZehnder interference fringe patterns. The arithmetic includes image preprocess(i.e. noise extraction of image)，gray image binarization and fringe pattern sharpening.
2005, 26(2): 43-46.
Abstract:
The opening sphericity is widey used in the metrology of radiation, the scaling of radiation and the measurement of laser energy. As taking the radiative heat exchange into consideration, the true emissivity is an important parameter due to multiple reflections at the surface of the sphere, so the energy absorbed by the opening spherical cavity is more than a flat plate.The article introduced the visible emissivity and ‘opening phenomena’——cavity effect which makes the emissivity and the absorptivity increased correspondingly. With the visible emissivity, the thermal loss of radiation was calculated.
The opening sphericity is widey used in the metrology of radiation, the scaling of radiation and the measurement of laser energy. As taking the radiative heat exchange into consideration, the true emissivity is an important parameter due to multiple reflections at the surface of the sphere, so the energy absorbed by the opening spherical cavity is more than a flat plate.The article introduced the visible emissivity and ‘opening phenomena’——cavity effect which makes the emissivity and the absorptivity increased correspondingly. With the visible emissivity, the thermal loss of radiation was calculated.
2005, 26(2): 47-50.
Abstract:
Based on the equation of the current continuity, the analytical expression of carrier and current densities is presented. In the calculation, the boundary condition is determined by considering the injection current that can be easily measured in experiments. We discussed the distributions of electron density and electron current density, analyzed the influence of electric field on the electron density, electron current density and recombination efficeiency, and investigated the effect of the electric field and potential barrier on recombination efficiency. The theoretical values based on the model are basically in agreement with the results that have been reported in the literature.
Based on the equation of the current continuity, the analytical expression of carrier and current densities is presented. In the calculation, the boundary condition is determined by considering the injection current that can be easily measured in experiments. We discussed the distributions of electron density and electron current density, analyzed the influence of electric field on the electron density, electron current density and recombination efficeiency, and investigated the effect of the electric field and potential barrier on recombination efficiency. The theoretical values based on the model are basically in agreement with the results that have been reported in the literature.
2005, 26(2): 51-53.
Abstract:
Under the conditions of ion beamassisted deposition (IBAD) using broad beam cold cathode and end Hall ion sources, utilizing the box type of Nanguang ZZS7001/G coater,the influences of two IBADs on transmissivity and stress have been demonstrated respectively.With the analyses of a great deal of experimental datas, the properties of the optical thinfilm got by IBAD with low energy and high current are better than that got by high energy IBAD. The reasons of the property variation of flim layers is analyzed and the processing parameters are given in this paper. The experiments show that IBAD with low energy and high current makes the layer properties much better.
Under the conditions of ion beamassisted deposition (IBAD) using broad beam cold cathode and end Hall ion sources, utilizing the box type of Nanguang ZZS7001/G coater,the influences of two IBADs on transmissivity and stress have been demonstrated respectively.With the analyses of a great deal of experimental datas, the properties of the optical thinfilm got by IBAD with low energy and high current are better than that got by high energy IBAD. The reasons of the property variation of flim layers is analyzed and the processing parameters are given in this paper. The experiments show that IBAD with low energy and high current makes the layer properties much better.
2005, 26(2): 54-56.
Abstract:
In this paper, the relationship between the emergent light ray angle and incidence point is investigated according to the principle of the geometric optics and the computer simulation experiment so as to obtain the dependence of the incidence point on the vertex angle of the prism, refraction index and the basal-plane length of the prism from MATLAB. The experimental result shows that a certain incident point of the incident light is required for the measurement of reflection index of a prism and the application of a spectroscopic instrument.
In this paper, the relationship between the emergent light ray angle and incidence point is investigated according to the principle of the geometric optics and the computer simulation experiment so as to obtain the dependence of the incidence point on the vertex angle of the prism, refraction index and the basal-plane length of the prism from MATLAB. The experimental result shows that a certain incident point of the incident light is required for the measurement of reflection index of a prism and the application of a spectroscopic instrument.
2005, 26(2): 57-59.
Abstract:
This article introduces a threeinone composite achromatic compensator.The continuous adjustment of retardation from 0 to 2π can be realized by rotating one of the wave plates.As for the compensator,it is characteristic of convenient adjustment, big adjusting range and high degree of accuracy. The theory and experiment show that the most important feature of this composite compensator is its achromaticity in a certain spectral range. the compensator can be used to polychromatic light because its retardation is independent of wavelength.
This article introduces a threeinone composite achromatic compensator.The continuous adjustment of retardation from 0 to 2π can be realized by rotating one of the wave plates.As for the compensator,it is characteristic of convenient adjustment, big adjusting range and high degree of accuracy. The theory and experiment show that the most important feature of this composite compensator is its achromaticity in a certain spectral range. the compensator can be used to polychromatic light because its retardation is independent of wavelength.
2005, 26(2): 60-64.
Abstract:
Optical coherence tomography(OCT) based on optical reflectance measurement of lowcoherence is a novel imaging technology that performs the noninvasive and highresolution fast imaging of high scattering media such as biological tissue.OCT could result in a significant reduction in the time, complexity and cost for the imaging of developmental morphology as compared with the conventional histology. The noncontact, noninvasion imaging with OCT in vivo can be used to track the development of single speciment.The use of highspeed OCT imaging technology of cardiac structures enables the functional imaging to be performed in vivo of these speciments.OCT imaging is conductive to the developmental research on the variation of function and morphology due to gene mutation. Applications in developmental biology are presented in this paper.
Optical coherence tomography(OCT) based on optical reflectance measurement of lowcoherence is a novel imaging technology that performs the noninvasive and highresolution fast imaging of high scattering media such as biological tissue.OCT could result in a significant reduction in the time, complexity and cost for the imaging of developmental morphology as compared with the conventional histology. The noncontact, noninvasion imaging with OCT in vivo can be used to track the development of single speciment.The use of highspeed OCT imaging technology of cardiac structures enables the functional imaging to be performed in vivo of these speciments.OCT imaging is conductive to the developmental research on the variation of function and morphology due to gene mutation. Applications in developmental biology are presented in this paper.
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