A new technique of white light pseudocolor density encoding is described. The exposure to the object to be processed is performed by means of a Ronchi grating in one step. According to the property of the negative encoding plate "the higher the transmittance, the lower the modulation", and when only the zeroth and the first orders of the spectrum of the grating are allowed to pass. Authors the positive and negative images have been obtained respectively, and hence realized contrast reversal. After color filtering, authors accomplished the pseudocolor density encoding.

A real-time image pseudocolor encoding method for spatial frequency and density encoding is presented. Pseudocolor images are obtained through color spatial filtering at a spatial frequency plane. The spatial frequency pseudocolor encoding is accomplished by two-dimensional color spatial filters. The density pseudocolor encoding is obtained through contrast reversal of color image, and the contrast reversal is accomplished by two-color halfwave phase filtering. ERTS and airborne remote sensing images are processed directly. Experimental results showed that this method is effective.

In this paper, a optical pseudocolor encoding method upon the difference between two photographs is presented. We show that the difference between two pictures with continuous change in gray which is discriminated simultaneously by eyes, can be detected by use of two sources of different color. The pseudocolor image from the optical system is processed in select-color and differentiation by video system, thus the signal of difference is enhancad. The theory is agreement with experiment. Finally, some applications are discussed.

A type of computer-generated holographic scanner, being able to scan any type of 2-D patterns such as characters is described. Methods of improving the focusing ability and reversing the soanning direction are introduced and the experimental results are presented.

The number of Fresnel half-period zones for complex optical systems is derived. It s formula is N=(a2/λ) [(A/B) + (1/R)] . Since it is expressed by the ray matrix elements, there is a universal significance. We have introduced a concept of "effective propagation path" Leff=B/A, which reflects the influence of optical system on the diffraction field. For several typical systems the concrete expressions of the Fresnel number are given. The imaging properties of the vacumm spatial filter are indicated using the ray matrix theory. The perfect image-relaying conditions are determined. Finally we extend the Fresnel number to the region of complex number, and use it to investigate the diffraction problem of a truncated Gaussian beam.

Starting from scalar diffraction theory, various possible recording and reconstruction geometries of one-step rainbow holography are analyzed, and quantitative conditions for obtaining orthoscopic or pseudosoopic reconstructed image are derived.

The parameters for a cousto-optic mode-locking of an Ar+-laser investigated. The stable mode-locked operations at 488.0 nm and 514.5 nm have been obtained. The average power is up to 300 mW. The pulse-width is about 200 ps. The fluctuation of the pulse amplitudes is less than 5%. A dye laser with an astigmatically compensated cavity synchronously pumped by this Ar+-laser has been operated. Its pulse-width is less than 10 ps, and the average power is about 20 mW at 584.0 nm. The pulses of mode-locked dye laser are wavelength tunable over the range 570.0~620.0 nm, Particularity，the effects of the mismatch of the cavity length oi frequency on the made-locking behaviour axe emphasized.

A folded tunable single-mode TEA CO2 laser with two beams has been described. This laser can produce two beams which have the temporal coincidence of the pulses. Each beam can be tuned by grating independently within the range of 9.2μm~10.9μm. The highest peak powers of the single-mode/single-line output and the multi-mode/single-line output are about 1MW and 4 MW respectivety. In this paper Authors discuss the optimum transmittance and the mode selection of this laser and the temporal coincidence of the pulses. Some experimental results are given.

On MTF thoery of the pushbroom imaging system using the CCD line array, the formula which is used to calculate, respectively, the MTF in the line direction and in the direction perpendicular to the line direction has been given in some articles, under a special condition of pushbroom motion perpendicular to the line. In this paper author derives a general formula which is valid for any direction and any angle crossed by the directions of the line array and pushbroom motion.

GaAs- (AlGa) As large optical cavity lasers have been fabricated using liquid phase epitaxy method and its main parameters, have been measured, such as laser pulse power, beam divergence angle, wave length and external differential quantum efficiency etc.

This paper reports the experimental measurements of gain characteristics of a XeCl laser pumped by Blumlein fast discharge device, using the method of varing output coupling, according to the relation between output power of the laser consisting of a stable cavity and homogeneously broadended gain medium, and other laser parameters, such as small-signal gain coefficient go, constant absorption loss coefficient saturation intensity Is and cavity length finally, the optimum transmittance of laser is determined. Authors find that the optimum transmittance is a function of pumping power.

The radio of signal to noise of passive modelocked pulse in high power laser system and extinction ratio of Pockells electro-optical switcher have been measured using Si photocondution switcher. The position and amplitude of prepulses have been observed. It s shown that measurement methods axe simple, reliable and more sensitive.

The paper presents a derivation of the locus equation of rectangular waveguide of which index distribution function is n(x) = no (1 - 1/2 Ax3). The locus of light rays can be described with logarithmic function as incidence plane is the central plane having refraction index no, and tne locus of light rays can be indicated with arc tangent function as incidence plane is in edge which has index of n(X). When tangential plane crosses no plane, the locus of paraxial rays locating in tangential plane is a well-known sinuous function. According to the locus equation^ this waveguide has a function similar to parallel plate or divergent lens or cylindrical lens. When it is used as parallel plate, the waveguide offers much larger displaceiueiiii than that given by a parallel plate wMch made of homogenous medium. As a divergent lens, the waveguide can not be used as image-forming element, becaug? it only acts when light rays have a certain angle with optical axis. The image-forming feature depends on the distribution constant A, the central refraction index n0 and the thickness Z0 Thus, the locus line may locate in the outside or inside or end of the medium. The waveguide may be used in optical systems. The paper places emphasis on deriving locus equation of light ray motion in the inside of tho medium according to eikonal equation.

This paper mainly presents the experimental research on the optical properties of high temperature, low density air using a 800 mm diameter shock tube and a radiometer. The experimental temperature ranges over 4380~7500K; the density ranges over 1.41×10-2~1.00×10-1 ρ0 (ρ0 is the standard density at sea level). The spectral wavelengths are 430.0, 540.0, 640.0, 720.0 and 1038.0 nm. The experimental results are compared with the theoretical and experimental results published by other countries and shown a good coincidence. The characteristics of flow field are given and the reliability of experimental results is analysed too.

By pumping a LiIO3 crystal with 1.06μm picosecond laser pulses train at a proper incident angle, 8 stimulated Raman scattering lines have been obtained at the visible region from 4896 A to 6119A:ω=2ω1±nωP, n = 1, 2, 3, concerned elementary excitations being LO mode and TO mode of (A+E1) oblique polariton in the crystal. The process of such a complex stimulated Raman scattering is as following: with phase matching intense 1.06?m laser beam and its scattering light generate SHG in the crystal; meanwhile it excites coherently the elementary excitations of the crystal，the latter scatter the SHG into Stokes and antistokes radiations resulting in a complex effect of and nonlinear optical process. Furthermore the reflected ward stimulated Raman scattering with distinct wavelength has been observed from the forward one. Present paper shows that the reflected ward scattering is also the SHG coherent Raman mixing but generated by the 1.06 μm beam reflected npon the exit crystal surface.

The measurement and experimental result of electrooptio effect in anodic Nb2O5 films are presented in the paper. It has been found that dependences of the change in indices on the field are different from those reported in previous papers. The power is 2 at higher field and 1.63 at lower field. Some hysteresis, but no permanent change in indices was observed.