On base of linearly coupled-mode equations, some characteristics of modefields and coupled power of a three- optical planar coupler with variable coupling coefficients are presented. The comparisons with conventional 3×3 coupler are also given. The experimental results obtained are in good agreement with the theoritical analysis.

A new method of decreasing connecting loss between Er3+-doped fiber(EDF)and single mode fiber(SMF) is presented in this Paper. The low connecting loss has been obtained by tapering Er3+-doped fiber, which makes the transmission mode of Er3+-doped fiber expand so that it matches the transmission mode of single mode fiber Perfectly. The connecting loss less than 1 dB has been obtained with this method in the experiment.

A real-time hybrid joint transform correlator, using a LCLV as input device and another one to record and display the joint power spectrum, is proposed according to the principle of joint transform correlation. Experimental results verified the correctness of system design and Performance analysis.

This paper analyzes optical transmission characteristic of moire fringes that appeared when two Ronchi gratings of the same frequencies are superimposed. A quasisine divided block can be obtained by selected the proper grating constant and be used in 3-D shape measurement. The experiment result shows that the method is simple and practical, and easy to realize automatid processing.

The Nd3+:La2Be2O5(Nd3+:BEL) is a biaxial crystal with monoclinic structure and space group C, C2/C. The fluorescence spectra are Polarization lines, the peak wavelength λ=1.07 μm for E∥X and λ=1.079 μm for E∥Y(b). The absorption,polarization fluorescence spectra (77 K°, 300 K°) and 4F3/2 fluorescent lifitime (τ=135±5 μs) of the Nd3+:BEL crystal were measured. The crystal is suitable laser material for LD pump based on the analysis of spectroscopic properties and comparson with Nd3+:YAG.

The prerequisites to the operation of passive mode-locking laser are derived quantitatively, which include the upper limit of pumping rate and the lowrt limit of the saturation intensity of laser medium.

Dynamic processes of the modelocked laser based on an auxiliary coupled cavity containing a nonlinear frequency-doubling crystal has systematically been studied in this paper. The specific formulas of the output pulse width of this modelocked laser in instantaneously dynamic equilibrium are given for the first time. And, our studying results show that the experimental results coincide with the theoretical calculations dramatically. Finally, we have also repored the dependence of this laser output characteric on some parameters.

A new path is put forward to enhance the fractions of highly ionized ions in laser-produced plasmas through a mixed process of resonant photopumping followed by electron collisional ionization. Modelling calculations indicate that the mixed process is effectiver to create the highly ionized ions. Experimental evidences imply the potential importance of theis process.

The constructional data and surface parameters of a tilted two-mirror optical system with eliminated spherical aberration, coma and astigmatizm at the center of the field may be sloved by analytic method. By ray tracing with those solved data, the image size at the center of the field is less than 0.2 arc second. For reducing the image at the outter part of the field, it is necessary to add higher order terms in the equation of the bicurvature mirror, and at the same time deviate some parameters solved by equations. For an F/11 system, we may expect 1.5″～1.9″ image spot size at ±0.6° field. The meridional and sagittal focal lengthes of such a system are not equal, the difference being less than 1%.

An approach to the search for a global minimum in the multidimensional design space of lens design the method of random sampling is presented in this paper.Comparison with the method of simulated annealing is discussed and two examples,doublet and double Gauss lens, are described.

A hybrid lens composed of a binary optical element (BOE) and a refractive lens can be considered as hybrid effective glasses. The combinations of a proper hybrid effective glass with an appropriate glass show the ability of correcting secondary spectrum. The method of finding power solution is given and choices of glasses are discussed.

Reseerch of experiment and numerical competition for the small scale thermal blooming instability is reported. The beam quality strehl ratio, the increase of perturbative energy, the competition among Perturbative terms and the temporal variation of beam radius in near-field are described.

In this paper, a new method to implement the Perfect shuffle[3] with the Dammann grating[1,2] used for optical interconnection is proposed. The combination of a 2×2 Dammann grating and an imaging lens is functional as a conventional lens composed of 4 off-axis subpherical lenses. The Position of the image point is determined by the distance between the Dammann grating and the output plane. Properly chosing the position of Dammann grating, we can realize Perfect shuffle with various density and various capacity. The theory and the experimental result was presented.

Under partially coherent light illumination the two-point resolution is analysed for the annular aperture imaging system by using the Sparrow criterion. The resolution is discussed as a function of two parameters, the spatial coherence condition of illumination and the central obstruction of an annular aperture. It has been indicated that the twopoint resolution is increased under partially coherent illumination and annular aperture compared with the coherent illumination and circular aperture.

The properties of the N th-power squeezing of field amplitude in the one-photon Jaynes-Cummings model of an atom initially in the ground state coupling with the coherent state are investigated in this paper. The variations of the degree of the squeezing with the initial average photon numbers of field and the Power of N are discussed.

The experimental apparatus for measuring the peak value of the Faraday rotation F induced by alternating magnetic field is set up. The sample used here is a magneto-optical film Prefared by liquid Phase epitaxy. By measuring the fundamental and the second harmonic of the photodetector current at a angle away from cross setting of P, A, the F can be calculated. The method is simple and accurate and can be used at any frequency.

Extension of the bandwidth is investigated for a waveguide free-electron laser (FEL) by adjusting the waveguide dimensions, or the electron beam energy, or the period and strength of the wiggler. A far-infrared FEL oscillator with the bandwidth of 400 μm is designed.

Single-longitudinal-mode, TEM00 output of 55 mW has been obtainded from a end-pumped twisted-mode cavity Nd:YAG laser. Continuous wave thresholds of ～300 mW have been observed with slope efficiencies of 23%. The linewidth is less than 25 MHz.

Using the Nd:YAG laser with the SBS-phase conjugate mirrow based on SF6 gas, the laser drilled hole on a 0.1 mm thik blade has been reported in this lecture.The primary experimental results show, that the fine hole with the exit diameter of 20 μm and the entrance diameter of 30 μm has been obtained due to the small laser beam divergence of this SBS-phase conjugate laser.

A numerical method based on the techniques of inverse Fourier convolution and nonlinear least squear algorithm, etc. is presented for obtaining high-resolved spectra of radiation sources. This method can eliminate broadenings induced by radiation sources and spectrographs, and can improve the spetral resolution of spetrographs. As an example, the method is successfully applied to the analysis of laser plasma spectra of Mg ions recorded by pinhole crystal spetrograph.

In this paper, we describe the method of measuring the duration and the coherence time of ultrashort laser pulses using the technique of transient grating induced by laser. The two beams from the same laser interfer in the nonlinear medium and induce an integrated-intensity grating. Measureing the self-diffraction signal intensity versus the delay time between the two laser pulses and using the forth-order coherence function, we can get the duration of the laser pulse and coherence time.

The relative spectral distribution of synchrotron radiation emitted by Hefei 800 MeV electron storage ring was measured in 300～800 nm range, by using quartz tungstan halogen lamp spectral irradiance working standard source. The polarization and the angular distribution were investigated at 405 nm. Within the experimental error, a good agreement was found between experimental results and values predicated by theory of synchrotron radiation derived by Schwinger. The difference of relative spectral distribution and the polarization is less than 5%.

Quantitative measurements of transmitted second harmonic generation (TSHG) through the germanium thin film versus the angle of Polarization of incident light from the interface between germanium film and K9 glass are presented. We calculated the intensity of TSHG by the boundary conditions and sipe′S hydrodynamics model, and found that the phenomenological parameter “a” which estimates the size of this normal components of the harmonic current has varying value with angle of incidence.

This paper presents a solution to recover intrinsic color features of objects for classification by using dichromatic reflection model and finite dimensional linear model for illumination and reflectance. At first the spectral power distribution of illumination is estimated. Subsequently, the surface spectral reflectance is derived with the help of the two models mentioned above. The normalized deviation spectral reflectance preserves only the contribution of body reflectance of the surface which is independent of illumination and geometric condition. Therefore, it can be used as the reliable feature for classifying color of the object. The experimental results and analysis about classification are shown in the paper.