In this paper the relation between apoohromatism and super-apochromatism of the optical systems and the relative partial dispersion of inorganic glasses are discussed and the application conditions of the dispersion formula of glasses are dealt with. Based on the dispersion formula and dispersion data of the glasses, the eigen absorption frequency in ultraviolet range, the vibrational absorption frequency in infrared and their oscillator strength of a series of glasses have been calculated by computer. The relationship between these properties and chemical composition and structure of glasses are also considered. Infrared and ultraviolet absorption spectra of a series of inorganic glasses have been measured. Good agreement has been found between the measured and calculated value of the ultraviolet outofF wavelength as well as the infrared absorption wavelength at the highest energy. In addition, the relationship between relative partial dispersion and chemical composition of glasses has been established and a method for calculating the relative partial dispersion of glass from ohemical composition are presented. By this method, the relative partial dispersions of about one hundred kinds of optical glasses has been calculated. Because of difficulty in measuring the relative partial dispersion, our calculation method can be used to oalculate and adjust the relative partial dispersion of optical glasses. The ohanging rules of the relative partial dispersion for various oxides and fluorides in glasses are analysed, which oan be used for designing new glass composition with anomalous dispersion.

Theory and experiments of a new stereoprojection technique that uses a white-light optical image processing system are described. The stereoprojection can be accomplished in two steps: (1) Spatial encoding of stereoscopically-coupled images, and (2) spatial polarization filtering at the Fourier plane in a white-light optical image processor. Comparing with existing stereoprojection methods, the present technique requires only one projector and a single piece of encoded film, therefore it is much simpler and more economical for practical applications. From the point of view of optical filtering at the Fourier plane, the polarization concept is new. If the spatial frequency of the Ronchi grating used in the encoding is high enough, there should be little loss in picture resolution.

The reconstruction properties of the dilute objects are different from the extended objects. The dilute objects can be reconstructed from a few of projections. In the case of the extended objects, the projection number needed for reconstruct is proportional to the number of resolvable elements. And the projection number cannot be decreased by means of augmenting sampling points in each projection. The depth resolution of the dot coded imaging is discussed as well.

This paper describes briefly a new concept for enhancing the resolution of microscope and gives the experimental results for low power and medium power objectives.

In this paper, a set of equations for retrieving phase from two intensity distributions in the image plane or some other plane of an imaging system was obtained by the exactly mathematical derivation. The equations are completely analogous to the algorithm suggested by Gerchberg-Saxton[1,2,4] and Misell [3]. We point out that, if the transformation between two wave functions is performed by unitary operator and one of the wave functions is absolutely square integrable, the phase reconstruction from the known intensity distributions in any two planes of an imaging system can be achieved using OS algorithm.

This paper reports the calculated results of electron energy distributions and transport coefficients in a discharge-excited mixture of HCl, Xe and Ne. The effects of the mixture gas compositions and E/N values on the electron energy distributions have boon discussed. Excitation rates, ionization rates and dissociation attachment rates have boon calculated by numerically solving the Boltzmann equation, and dependences of these rates on E/N value and Xe partial pressure has been discussed.

In order to obtain tunable, very narrow linewidth laser radiation of high power and energy, we have developed a self-injected tunable dye laser based on a new technique. In this paper the theory of mode coupling in dye lasers is used to study the relationship between tunable bandwidth range and injected power. It is shown that the tuning range of a self-injected dye laser is associated with the injected power p and the state function of the amplifying cavity; when the switching time of the cavity switch (Pockel cell) is fixed, the tuning range increases almost linearly as the injected power increases. The experimental results agree with the theoretical analysis, which is useful for actual injection laser devices.

This article discribes a comparative method for experimental determination of SHG coefficients of some crystals. With the d36KDP as a reference standard, we measured both d36KDP and d31BNN, d32BNN of several samples of BNN crystal. Their results show that the coefficient d32RNN is sensitively related to the stoichiometric composition of BNN crystal. Some discussions concerning the nonlinear optical properties of BNN crystal are also presented.

The sensitivity of CCD pushbroom scanning imaging system is analyzed systematically. The equations for system s NEΔρand MBΔρ are derived, and An exhaustive study of the system s MTF is made. Especially, from the scanning and operation characteristic of CCD, we differentiate the convolution and interval integration process on the Y-direction from the sampling process on the X-direction. And the integration MTF4 on the Y-direction is analyzed severely. The exact expression of MTF4 is obtained as follows

This paper describes a method of "optical tracing" used to measure the energy distribution on focal plane of an imperfect processed optical system. It is similar to Hartmann method. High brightness He-Ne laser with TEM00 mode output is used as a probing beam. A parallel beam passes through a movable aperture and is focused by a local part of optical system to be measured. Then we determine the position of central point of Airy spot on the focal plane. The spatial coordinate of the point is magnified to 40X by an objective and read out by microscope. Coordinate of each central point of Airy spot corresponding to each local part is obtained if the aperture can be moved in the whole optical system. In the case that the optical system is divided into m parts by the movable aperture, there will be m points on focal plane. The ratio of the point numbers on a local part of the focal plane to to is proportional to the relative energy of incident beam focused on it. The accuracy of this method can be up to the magnitude of Airy spot diameter of the whole optical system. The movable aperture is defined as 1/10 of that of the optical system, since the accuracy determining central point of Airy spot of the movable aperture can be up to 1/10 of the spot diameter. The focal spot size and energy distribution on focal plane of aspherical-gpherical lenses for laser-plasma interaction research have been measured using this mathod. It provides basis for improving lens processing and calculating the energy density on target plane.

The optically regenerative Q-switch method, by which the laser output can be stabilized, is simple and easy to operate. But the disadvantages of laser prepulses inevitable and the successive pulses easily produced severely limit the applications of this method to laser amplifiers and laser range-finders. To overcome these shortcomings we have designed a new method using axial superradiant signal to trigger the Q-switoh. The principle is as follows: The superradiant signal intensities near the axial correspond to certain population during the laser process of the optical pumping. So we can oontrol the population whioh can trigger the Q-switch by controlling the superradiant convert electrioal level in the superradiant deteotor and then the laser output can be stabilized. ISfear the laser threshold the variation of peak heights of laser pulses controlled by ■superradiant signal triggered Q-switch is reduce^ to only 1/4 of original value when we change the voltage of xenon-flash lamp near the laser threshold. The laser output reproducibility may also be improved by this method.

A new type fast-response detector is recommended. This pyroeleotrio detector is made of LiTaO3 and LiNbO3 crystals, having very strong absorptive characteristics for laser at certain wavelength. In this paper, the consideration in device design, the selection of materials, the fabrication and performance of such device are described and finally, its prospect for the monolithic pyroelectrio array is briefly dissoused.

This paper presents optical Fourier transforms having been used to measure wavelengths and orientation of sea waves in the Jasin area of the North Sea, that is located approximately 200 km north-west of Scotland. Input films were obtained from a synthetic aperture radar (SAR) borne on a satellite. The research work was carried out in Blackett Laboratory, Imperial College of Science and Technology, using optical Fourier transform equipment. The Institute of Ooeanographio Science provided us with SAR films as well as a grant partly. Comparing the results obtained from direct measurement on the sea, or using the computer to calculate optical Fourier transforms of the input films of sea waves, with that obtained from our method, it is obvious that this method is quicker and more reliable. Under the guidance of Prof. W. T. "Welford, the researoh work was completed by Canadian academic visitor, Dr. R. A. Lessard and the author jointly. I would be grateful to those who might point out any error which I made in this paper.

A new type of beam expander suitable for pulsed dye lasers is described. The system is small in volume and has a large expansion ratio, low loss and a high degree of polarization. Calculations for the design and experimental results are given.