A technique for recording and reconstructing a double-pulse exposed hologram of particle field is proposed. The feature of this technique is that the image of particle field at different pulse duration can be reconstructed separately. Thus they can be A/D converted, stored, processed and pseudo-color encoded separately but shown on a monitor simultaneously. The key of the technique is to make the object waves or reference waves of two light pulses propagate in different paths during hologram recording, by using an electrooptic crystal and a polarizationb eam splitte,r and to perform spatial filtering during reconstruction. Experiments have demonstrated the feasibility of this technique.

The interferogram is usually obtained with a low unconstant S/N rate in engineering interferometry, which makes it very difficult to analyse the fringe pattern by using fringe thinning and fit method, and causes larger test error. The Gaussian threshold method introduced in this paper can overcome the disadvantages of some ordinary techniques widely used now. It is certified that this method has high accuracy and reliability by the analysis of computer simulated results and real tests. The principle and algorithm of the Gaussian threshold and the results of tests are presented in details.

In this paper a direct and minute discussion is given of power conservation for volume gratings, based on the calculation of diffraction efficiency. It is shown that two-wave coupled-wave theory do not rigorously conserve power under the weak-coupling assumption.

This paper first considers tne effect or me crystal field on both of tne 4f ground state and 5d excited state of Ce3+ ion in the paramagnetic medium CeF3, and further, takes account of the splitting of the ground state in the crystsl field caused by the effective superexchange field Hv and applied field He, and then using the model of the double transition with ground state splitting, calculates quantitatively the specific Faraday rotation θF, Verdet constant V, magnetic susceptibility X and their temperature dependence in CeF3. A theoretical calculation shows that the magneto-optical effect and its temperature dependence in CeF3 are closely related to the superexchange interaction between Ce3+ ions. V-1 is linearly dependent on T and V/X=-16032(1+68.1/T) in the temperature range 60<T≤300 K. The theory is in good agreement with the experimental results.

In this paper, the performances of an optical multivalue neural network named Positive-Complemental Model (PCM) are evaluated, which includes storage capacity, tolerance and convergency. The results obtained by computer simulation in the network (N = 16) show that the performances of the optical neural network with PCM are improved.

A new type of small-period wiggler free-electron laser is proposed and investigated numerically with the three-dimension self-consistent nonlinear theory. The results show that a radiation with power of 20 MW and wavelength of 1.7 mm can be obtained on a relative low energy accelerator (0.5 MeV, 800 A). The design of the small-period wiggler free-electron laser for overall experiments is presented.

Green light can be efficiently generated by intracavity-doubeling under Q-switch at a high repitition. Its dynamic characterises are studied in this paper. The optimum coupling coefficient is a function of initial inversion population. A home-made MQW-LDA with an output power of 200 mW is used in our experiment to pump a Nd:YAG laser with accousti-optics Q-switch and KTP intracavity-doubling. SHG output energy of 0.4 μJ has been obtained with the pulse width of 70 ns.

The self-starting mode-locking and the time-dependent modulation characteristics of a coupled-cavity laser(CCL) with a gain medium in an external cavity is discovered theoretically for the first time, and analysed and calculated in detail. Its mechanism is explained in this paper. We suppose that there will be a possibility to use a CW pump source in stead of a mode-locked pump source and to get shorter pulse in mode-locking CCL.

In this paper we propose a new method of the measurement of the Doppler frequency shift due to the moving grating inside a BaTiO3 crystal when a self- pumped phase conjugate mirror is coupled to a ring dye laser. The experimental results show that the Doppler frequency shift is less than 0.2 Hz. Furtheremore, the analysis indicates that the Doppler frequency shift cannot be Used to explain the wavelength self-scanning initially towards the longer wavelength.

For Ti diffused Z-cutt LiNbO3 optical waveguides and its polarizer structures with metal cladding/ dielectric buffer layer, technological parameters of the single- mode waveguide and absorption losses of the fundamental mode are theoretically analysed at 1.523 μm wavelength of the He-Ne laser. Moreover, TE0mode polarizers of Ti:LiNbO3 optical waveguides are developed using the resonant absorption effect of TM0 modes for the first time at 1.5 μm wavelength. When the polarizer lengths are 2 mm and 9 mm, its extiction ratios are 20 dB and 25 dB, respectively.

Imaging formulas of Gaussian beams in nonlinear conical GRIN rod lenses are derived from the variational method and the ABCD law. It is shown that the imaging properties and the ray paths of such lenses depend on the optical power. The imaging formulas reduce to the known results when n2=0 ( n2: the nonlinear coefficient) and under the geometrical optics approximation.

A new feature will be exhibited in the absorption-dispersion relation if quantum coherence is induced by an external field in the medium consisting of atoms of V-type energy-level configuration. In particular, when a weak light of a certain frequency travels in the medium, the refractive index can be larger than 1 where the absorption vanishes.

We have measured the absorption and fluorescence spectra from the solution of the mixture of C60 and C70 in toluene. The SHG output from a Q-switched YAG laser was used as excitation source. Two Fluorescence peaks were observed at circa 670nm and 695nm, which may originate from C70 molecules.

There is a characteristics drift caused by the photorefractive effect in Ti-diffused LiNbO3 waveguides. The drift will result in severe problems to the devices in pratical use, especially to that based on optical coherence principles. Experimental results about thermal fixing technique of waveguide characteristics are presented in this paper. It is derived from our experiment that H+ ions do not play an important role in thermal fixing processing.

The phenomena of longitudinal mode quenching in a CuBr laser with two types of multiple-mirror compound resonators are reported. The multiple mode-locking pulse trains at a repetition rate equal to a multiple of the fundamental longitudinal mode spacing have been obtained. The highest repetition rate is up to 440 MHz. The experimental results indicate that the mulptiple mode-locking pulses at high and wide-range tunable repetition rate in CuBr laser can be generated by adjusting the structure parameters of the compound resonators, without shortening the length of the active medium.

In this paper, we presented a rectangular waveguide method to calculate the birefringence of an elliptical inner caldding single mode fiber. The fiber is approximated by a rectangular waveguide, then Marcatili and fective ndex ethod were applied respectively to calculate the birefringence caused by the elliptical clading. Numerical example was given and calculated results were compared with that obtained by plane wave approximation, modified coupled mode theory and perturbation method as well as exact values by solving the eigen value equation. It is shown that rectangular waveguide method is not only accurate but simple.

The Raman spectra of BSA in 5% aqueous solution extracted by nitrobenzene have been studied. The amide I band appears at 1 651 cm-1,amide Ⅲ band appears at 1 292 and 1242 cm-1. The characteristic Raman bands of the tyrosine residue are at 856、828 and 643 cm-1. The band of the s-s bond is at 522 cm-1. All the characteristic Raman bands of mis protein peptide prove that its structure consists of a- helical and random- coil. The tyrosine residue is "exposed" and the conformation of the carbon atoms in the disulfide bridge C-C-S-S-C-C is trans-gauche-gauche.

The XUV spectra of 5d8-5d76p transition array of Pt Ⅲ ion is predicted with the aid of the multi-configurations HFR method. The wavelengths, energy levels, oscillator strengths and radiative transition probability are obtained and these results are analysed.