2004 Vol. 25, No. 1
Using bidirectional reflectance distribution function,the scattering of visible light from a spatial object the scattering of solar radiation which is reflected by cloud are calculated. Based on the theories of heat transmission and background radiation, the thermal balance equation is established according to the law of conservation of energy. Take balloon as an example, the temperature and radiation power which vary with time, height and geographic location are calculated.The general law of infrared radiation characteristic of spatial object is analyzed.
The electron beam ion trap(EBIT) and the electron ion source(EBIS) are new instruments for the study of X-ray produced by very highly-charged ions when they interact with free electrons. Some of the design and physics features of EBIT/EBIS are described, and the characters of the X-ray produced with them are described too. Micro-focal X-ray can be taken out if focusing the ion beam with the ion-optical system.
The analytical result of Fraunhofer-Diffraction of the circular ring is known but that of the similar circular ring isn't. Based on Kirchhoff diffraction integral formula, the analytical result of Frauhofer-Diffraction on the similar circular ring is derived in this paper. Utilizing the relations of curve coordinate and Fourier-transform of similar circle. The diffraction patterns of the several typical similar circular rings are given and analyzed.
A transfer-matrix method is used to study cylindrical wave reflection at cylindrical media interfaces. We find that the reflection can be total at an interface of small radius but is only partial if the radius is large. This feature is useful for designing optical sources and receivers of small radii. Cylindrical-wave multi-cylindrical-layer antireflection coatings are also studied. We find that conventional quarter-wavelength layer designs cannot be used for these coatings and new design principles are outlined.
Based on geometric construction,the optic axial angle in the biaxial crystal has been derived from the new methode, which is introduced in this paper.The conclusion is justified by theoretical derivation.
Zoom optical systems have been widely used on all kinds of optical instruments,and more and more new design methods have been employed. Maybe all designers need the innovation to proceed with the design of optical imaging instruments. In this paper a rapid computing method of zoom optical design is reported, which can be applied to initial solution of optical system, sample computation in design process, check and audit of design data, resolve of driving cam curve in structure design and aspect design etc. The examples listedin the paper show how fine this method is in the design of a zoom system.
Three-thin-lens null corrector is generally made up of three singlets, which can be used to correct aberration caused by other optical components. Based on third-order aberration theory, the aberration characteristics of the three-thin-lens corrector are analyzed, and a method to solve the initial structure of the corrector and the corresponding formulae is given. These formulae are proven to be correct through a practical example.
In order to improve the computing method of lens automatic design and take human experiences of optical design into account, an intellectual expert system is used to control and solve the nonlinear non-equations by means of making varied cost functions,the linear list-square method and the single method in variable of dispersion. In solving, the glass variable and thickness are substituted to eliminate constructions in non-equations. The coordinate element are introduced to balance changes of variable.
Proceeding from the analysis of subjective method of MRTD measurement, an objective method of MRTD measurement, based on Artificial Neural Network and planar CCD, is proposed. The theories frame, design project and test process of the objective measurement system are introduced and the technical problems are discussed in this paper.
In this paper, it is discussed that how to selecte wavelength for space-to-ground laser communication.The condition factors which effect space-to-ground optical communication system,such as atmospheric channel, communication link,APT link,laser power,detector, etc.are analyzed.All this can help us to understand space-to-ground laser communications deeply and make a system design perfect.
The expressions and distribution curves of the optimal transmissivity for four-level inhomogeneously broadened single-mode laser are given, and then compares them with those of homogeneously broadened single-mode laser.The characteristics of the inhomogeneously broadened single-mode laser are described.
The research on passive fiber switch is attracting the people's attention in the optical communication. In this paper a new Magneto-optical crystal material used in the fiber switch has been researched theoretically and experimentally.It is decided that the fiber switch made of the material can work in the wavelength rang of 0.5～1.5μm, the excitation pulse current for the switch is lower than 4A and the pulse duration is about 5μs.
In the general, the higher the modal birefringence of fiber is,the better the polarization state maintaining of fiber becomes. Polarization-maintaining fiber is a specific type of single-mode fiber.Pointed out that its modal birefringence is relative to the factors of temperature, refractive index difference of core and clad as well as ellipticity, thermal expansion coefficient, diameter, elastic modulus,Poisson ratio, frequency, wavelength, drawing tension etc.The relationship mentioned above is described.
The principle and structure of rice microspore microscopy image collection and analysis system are discussed. Make use of colour information of the cell microscope image to complete threshold segmentation. According to the cell characteristics, the arithmetic of signature recognition in morpha and statistic is proposed. The experimental result shows that the method is fast and effective, and has been applied in the study of agrobiology.
Based upon the specifications of the extremely narrow-band interference filters in DWDM systems, it is indicated that application of λ_0/4 regular thin film assemble is the most optimal choice in production of such filters. Also, the different layer sensitivity distrbution and the error created in specific layers are analyzed, and random error simulation for several layers is given. Through the investigation into error compensation mechanism in direct turning point monitoring method, it is pointed out that turning point method is up to date the effective way to manufacture such filters, and two types of possible systematic errors are discussed in the end.
In this paper,the research history, deposition methods, characteristics and the applications of LB films in the optical field are introduced.The factors that have effect on the quality of film deposition are analized. The prospect of the LB film, which will be used in the optical field,is pointed out.
The application and principle of various kinds of domestic-made lensometers are described. Some automatic lensometer from abroad are also discussed in considerable detail. The structure and working principle of the visual type lensometer,projection lensometer and automatic lensometer are presented separately.The main characteristics and advantages of all kinds of lensometer are introduced.
The result of optical measurement,which is affected by the factor of atmospheric refraction,is discussed. Based on mathematical model between atmospheric refraction and angular measurement error, data processing with high precision is obtained with the computer software. The software of data processing has worked well in a weapon trial field.
The method of automatic collimation of multispectral and multibeam axes—infrared,TV and lase axes is introduced in this paper. It's pointed out that in the design of a weapon system, a collimating prism box should be installed behind the electro-optical instrument, if the condition is permitted, to control the electro-reticule generator or other functional elements added in the circuit, and make the weapon system realize the automatic collimation during flighting or driving.