This paper discusses the composition and optimum design of the computer originated holographic optical elements (COHOE). The preliminary experimental result with a special wavefront is presented.

This paper discusses a method for making a holograms of great depth by using. multi-beam objective waves with path differences of even multiples of cavity length. A commercial He-Ne laser with cavity length of one meter was used to produce a hologram of 8.2 m depth and 5m2 area. This method may open a promising prospect for holographic recording of large engineering structures with commerical lasers.

The design and calibration of soft X-ray telescope and synchrotron radiation monochromator require a knowledge of optical properties of mirror surface for various mirror materials over a fairly wide range of grazing angle and photon energy. For this purpose, the reflection and angle resolved scattering curves of four mirror samples (fused quartz, optical glass, zerodur and electroless nickel) were measured in the photon energy region from 0.1 to 1keV at grazing angles from 0.6° to 30°. The measurement was oaxxied out at the beam lino 11 is mainly used for the Baker grasshopper monochromator and PP xeflectometer. All the samples were polished by CIOM*. The rms roughness of the sample surface were measured by the stylus method at KEK** and CIOM successively. It was in the ordex of lnm. The electroless nickel sample was formed by plating an aluminum disk with Kanigen. A part of the results shown in Figs, 1 and 2 are of electroless nickel which is more often used as a mirror material in soft X-ray telescope and synchrotron xadiatio nmono-chromator.

A method for the measurement of optical path difference by phase difference of optical beat is discussed with respect to a Gauss beam from a twin-frequency laser with its light frequency and frequency difference stabilized. The measurement of tiny path difference is performed bv this method with a measurement sensitivity of the order of 1A.

Stable high-power single-mode operation of a Nd3+: glass oscillator with an unstable ring resonator has been achieved by using a LiF:F2- crystal passive Q-switch. The experimental results are disscussed.

IR intracavity optical parametric oscillation is obtained by using an electro-optic Q-switched Nd:YAG laser as the pumping source and a 50°-cut LiNbO3 crystal as the oscillator. The wavelength is tuned by varying the temperature of LiNbO3. The tunable range is 1.47～4μm with output energy over 100μJ per pulse and linewidth less than 5cm-1. This OPO has been applied in laser chemistry with good experimental results.

The inherent external mismatching angle is used to represent the phase mismatching caused by inhomogeneity in refractive-indices of doubling crystals. A new method is presented that can measure this important parameter accurately. The small-signal conversion efficiency is measured under a laser intensity of about 20 MW/cm2. A reference KDP crystal is used to eliminate laser-induced fluctuations. The experimental data are compared with theory in determining the mismatching angle of crystals, Δθc, as listed in Tables II，III, Among doubling crystals those with high conversion efficiencies can thus be selected readily. For some of then L, the high conversion efficiencies have been born out experimentally.

An |P,|W method for designing optical elements with axial-gradient indices is presented. The aberration requirement for a system is replaced by requirements on structure and index gradient by means of | P and |W expressions of primary aberration coefficients. The use of the method is not limited to simple lenses with gradient indices. It can also be used conveniently in the design of systems having homogeneous-medium elements.

In this paper, a method for measuring the time-resolved spectroscopy of high-repetition-rate short-pulse xenon flashlamps is described. Experimental results obtained with different electric gradients and operation conditions (simmer or no simmer) are given.

In this paper, a simple optical model for detecting suspended sand concentration by remote sensing is proposed based on the two-flow theory of radiative transfer in the sea. This optical model is more accurate than the "Logarithm model", while its mathematics is simpler than the Monte Carlo method by H. R. Gordon. Experimental results obtained in a water tank are presented and compared with results of the proposed optical model.

A Raman-shifted fundamental probe beam at 1.115A in a CCl4 cell has been obtained. The beam was then frequency-doubled in a KDP crystal to 5575A. The probe beam can be used for diagnostic of laser-produced plasmas.

Passive mode-locking of a XeCl laser is achieved by using PTP and naphthalene as saturable absorbers for the first time. In a compact laser cavity with "soft focus" arrangement, modulation of 90% and pulse train of 4～5 distinct 3-ns spikes are obtained. The total energy of mode-locked pulse is 6.3mJ with a beam spread angle of 2 m rad.

In the paper it is reported that using a prism-fiber coupler, the propagation coefficient βmn for scalar modes travelling in optical fiber can be determined by measuring coupling angles or positions of m-lines. Each scalar mode can be excited by varying the coupling angle. The so-called m-line corresponding to each scalar mode is coupled out of an output prism. Its characteristics are different from those of the m-line coupled out of a planar waveguide. The degeneration of βmn is shown on the m-line photograph. A good agreement is obtained between, the measured and calculated values of βmn.

In the paper, a measuring method of the stimulated Raman scattering (SRS) of diffused N2 in solid silica optical fiber is proposed. It is a new type of Raman gain medium-gas in glass. The dependence of threshold and linewidth of SES on the power of pump light is discussed. The output mode is measured when the transmission wavelength in the optical fiber is lower than the cut-off wavelength of the single mode silica optical fiber. In addition a week coupling mode between N2 and SiO2 molecules is observed in the experiment.

An optical bistable device based on Eaman-Nath acoustooptic diffraction is reported. Intensity curves of diffracted light from a Raman-Nath acoustooptic modulator are recorded. The bistability of the first-order diffracted light intensity as a function of the input intensity is presented. Three modes of operation are possible for this acoustooptic bistable device. As a potential application, the acoustooptical bistable device can be used as a multi-channel switch.

An experimental set-up consisting of a measuring device of magnetooptic rotation and a quarter-wave plate is used to measure the magnetic circular dichroism (ellipticity tanh θ") of (BiTm)3(FeGa)5O12 single crystal films and the change of θ" as a function of the magnetic field intensity H and sample thickness 2h. The measuring accuracy is 0.01°. Experimental results have proved that the imaginary part of magneto-optie rotation is also related to the magnetization intensity M just as the real part, and that it changes linearly with the sample thickness.

Laser induced damages in Nd: glass and KDP crystal for pulse duration from 13 to 70ns have been studied. The results indicate that the electric-field threshold for the laser induced damages in transparent dielectrics is inversely proportional to the fourth root of the pulse duration.

The formula for the sensitivity factor of reflectance of ambience-film-substrate systems to the change of film thickness is derived. Computer simulation is carried out for three different systems, and curves representing the dependence of the sensitivity factor on the angle of incidence are presented. A discussion for the choice of the angle of incidence in ellipsometry based upon results of computer simulation is given.

In this paper the effects of absorption peaks on the optical properties of some fluoride films after heat treatment (or moisture removal) are investigated in different gases. The mechanism of heat treatment in improving stability and hardness of the films is discussed.