A method to analyse propagation characteristics and loss of the metal-clad graded-index optical waveguides is proposed. The propagation constant and attenuation coefficient are calculated by using perturbation and multi-layer approximation for graded-index waveguides with the aid of recursion formulas. Metal-clad waveguides with typical refractive index profiles are analysed and discussed. The numerical results of this method agree well with those by exact numerical calculations.

The reconstruction methods of phase information "Frozen" in an electron hologram are discussed. The experimental results show that the double-exposure can not only obtain directly the phase information, where it doesn' t need laser reconstruction, but also gives quantitative results. This means that the information of both amplitude and phase can be simulaneously obtained in an experiment with electron microscope.

A general approach to implement bipolar neural network in a single channel vector-matrix multiplier is proposed. Bipolar performances are achieved by using unipolar data and introducing an additional neuron into the network. Minor modifications of the optical system and the formation of the enlarged nonnegative memory matrix are presented. Results of computer simulation and optical demonstration in case of bipolar bidirectional associative memory are also provided.

In this paper, a new method for extracting speckle fringes of a holo-specklegram is presented. It is proved theoretically and experimentally that when the interrogation of a holo-specklegram from point to point is used, the fringes in the two side lobes are the Young's interference fringes of the first-order diffraction in the holo-specklegram and is identical with the central Young' s fringes. The two side lobes fringes have high contrast and no effect of background halation. It is processed by using computer digit image processing technique and the in-plane displacement of a static load object is calculated quantitatively.

This paper analyses the average dispersion effect of the dispersion elements of the spacial wavelength multiplexing image transmission system. Image quality of fiber image bundle system is studied with line spread transmission function. Based on the optical imaging eigen theory, the mechanism of image quality improvement of the image bundle system with wavelength multiplexing is analysed utilizing image bundle imaging information, and the above analysed conclusion is examined by experiment.

gradient index; Gaussian beam; matrix optics; optical system design

The effect of phase and amplitude fluctuation of lasers on the time-delayed laser-induced double gratings (TDLIDG) caused by thermal effect has been analysed theoretically in this paper. It is found that the modulation amplitude of four-wave mixing signal decays as the relative time delay between two pump beams increases. Experimental results agree quite well with the theoretical predication. We also demonstrated that, when TDLIDG was employed for the wavelength difference measurement, the accuracy could reach the same order of magnitude as the laser linewidth.

A stilbazium salt polystyrene was synthesized as a pre-polymerized organic material for Langmuir-Blodgett (L-B) film fabrication and nonlinear optical property study. This material can form stable monolayer on a water surface to be transferred onto solid substrates. Second harmonic generation (SHG) studies on monolayer showed that the second order polarizability per chromophoric group of this material was 1. 2× 10-28esu. Multilayers of two different types of this material have also been fabricated and studied by SHG measurement. The results are discussed.

The liquid crystal spatial light modulator used as a stationary encoding mask of Hadamard Transform Spectrometer is described in this paper. The defect of the encoding mask is studied, and a measure of compensating for the defect is proposed. Some analog experiments demonstrate that the compensating measure correct.

Imaging rule of single selfoc lens and lens arrays is discussed. The optical parameters and size of single selfoc lens can be adjusted to produce required conjugate length and resolution of arrays. Practical arrays used in copying machines have been designed. The manufacture technique of arrays is preliminarily introduced.

The phase properties of the field in the Jaynes-Cummings model with an additional Kerr medium are discussed from the point of view of the new phase formalism of Pegg and Barnett. The phase probability distribution, the expectation values and the fluctuations of the Hermitian phase operator and the phase fluctuations are obtained. The effect of nonlinearity interaction of Kerr medium on the phase properties are analysed in comparison with the standard Jaynes-Cummings.

The optical multichannel analyzer (OMA) is a modern instrument for mesuring spectra. But there is a contradiction between the spectral resolution and the mesurable width of simultaneous spectra. In this paper, a method has been given out which can enhance the resolution ten times or even one hundred times without reducing the width of simultaneous spectra. The high resolving spectra of an OMA system can be easily obtained with this method.

The transmission and reflection spectra at wavelength between 0.2 and 6.0 μm, and photoluminescence spectra of Cd2SnO4 films deposited by RF reactive sputtering from a Cd-Sn alloy target have been measured. The optical properties of Cd2SnO4 films are analyzed and calculated theoretically in detail.

Nonlinear Raman spectrum of various of liquids is detected by using pulsed photoacoustic method. The cause of limiting the detect sensitivity of PARS techenique, mainly due to linear absorption, is discussed. Furthermore, an improvement method, differential method, is used to elimnate the disturbance from linear absorption. The detect sensitivity of PARS techenique is increased, so that the Raman spectrum of low concentration matter and the weakline of Raman spectrum can be detected. The probability of using differential PARS techenique to detect contaminant is discussed.

The reverse saturable absorption and optical limiting effect in pure fullerene molecules C60and C70are reported. The discussions on the influences of concentrations and life-time of triplet states upon the critical energy fluence of optical limiting are given. The absorption induced by the transitions of triplet states of fullerene molecules exhibits a saturable process which is demonstrated for the first time to our knowledge. This phenomenon is reported and its influence on optical limiting is discussed.

The spectra of argon excited by alpha-particIes with about 5.5 MeV emitted from 238Pu have been measured by using a home made single-photon counting system consisting of a monochrometer, photomultiplier tube (PMT) and single channel ect.. Twenty-nine spectral lines between 300-600 nm are successfully identified. The variation of the intensity of some lines with argon pressure is given. The lines of 472.8 nm, 487.9 nm ect. would be possible nuclear pumped laser lines in consideration of a simplified population analysis.

A new kind of dye LB films, in which dye molecules formed H-aggregates units with a shift of absorption band in voilet direction, is reported. Invertable optical recording effect has been observed in the LB films in the three-dimentional degenerate four-wave mixing experiment. The accumulating recording time needed to build up a stable grating in the film is about 80 ns(coresponding with 10 pulses) with the recording intensity of pulse beams of 30 MW/cm2. The main mechanism of the optical recording effect in the film is the light-induced transformation between H-aggregate and monomer structures of dye molecules, based on the po;ulation grating model in simplified three-state system.

Investigations of photon- gated spectral hole burning and its mechanism for the inorganic material BaFCl0.5Br0.5:Sm2+ are presented. Multiple holes burning, hole erasing and repeatable hole burning were realized. Gating ratio and hole stability were also measured. The experimental results indicated that more than 1×103 persistent spectral holes within an inhomogeneously broadened absorption band of BaFCl0.5Br0.5:Sm2+ at low temperature of 4 K could be burned.

The effect of three kinds of halides on SERS signal of molecule salicylic acid was investigated. It was observed that the SERS signal was quenched, instead of enhanced when halide anions were added into the silver sol and salicylic acid system. The efficiency of quenching related to the concentration of halide anions was studied. Time-dependence confirmed that the formation of quenching is probably a fast process.