A simple and efficient finite difference method is proPOsed to solve the eigenvalue equations for planar optical waveguides and circular fibers with arbitrary refractive index profiles. The compunction programs are simple and there is no need of explicitly evaluating Special functions. It can give accurate data for dispersion characteristics, cut-off frequencies and modal fields.

This peper presents a method for measuring rigid body motion by white light digital speckle photography. Instead of using laser beam to generate the Young's fringe pattern from a specklegram as conventional speckle photography, a digital Fourier transformation is employed yield the Young's fringe pattern from whiCh rigid they motion can be computed by a new FFT phase shift method. Moreover, a new technique for improving the quality of the Young's fringe pattern is given. Theory together with experiment is demonstrated.

In this paper, Orthographic dual- object beam holographic interferometry limited-view CT technique is suggested. Using this technique, object field informations simultaneously is obtaniced from orthogonal dual-directions. Temperature field of a cross section of thermal air flow for burner is reconstructed by circulating algebraic iterative relax mwthod with satisfied reconstructed accuracy. Reconstructed temperatures is identical with the measured temperatures using four thermocouples.

Polarized phase-modulation method is used to measure small birefringence with high precision. The effects on measuring results caused by some kinds of error sources in this method using PMCSA form for measuring opticaloisk substrate are analyzed. Results ontuined show that the presision is within 0.03 nm.

The operatins characteristics of a 1064 urn sinsle-frequency tunable diodepumped Nd-doped (2%) YVO4 laser are described. Tuning is accomplished by means of a piezo-electric transducer (PZT) mounted on the output coupler for cavity length control and the laser crystal heatins. The laser has been tuned over a range of 47 GHz without mode hopping. The tuning coefficientS up to 150 MHz/V for PZT and temperature coefficientS -1.04 GHz/℃ for the gain center frequency are demostrated.

A Q-switched intracavity frequency doubled Nd: YAG laser end pumped by two POlarization-coupled 1. 5 W laser diodes is reported. The maximum peak power of 2.23 kW at 532 nm with the pulse width of 18 ns and the repetition rate of 1 kHz is obtained. The highest repetition rate is 30 kHz, and the maximum average output power is 128 mW for the 532 nm laser at repetition rate of 15 kHz. The dynamic characteristics of LD pumped Q-switched intracavity doubled Nd:YAG laser are studied theoretically.

A set of space-dependent nonlinear coupling rate-equations has been established todescribe a CW self- frequency- doubling NYAB laser. Using these equations, the characteristics of the LD-pumped NYAB CW laser operating at 1.06 μm and 0.53 μm are studied by computer calculation. The influences of the spatial distribution of pump beam and laser beam, the optimum length of crystal and the optimum transmission of output mirror on laser output power have been discussed. Some design criteria. for experiments.

A prelase Q-switched and mode-locked Nd: YAG slab laser side-pumped by a quasi-cw 60 W laser-diode-array is described. The mode-locked pulse width of 36 ps is obtained. The energy within the 400 ns Q-switched pulse envelope is about 280 μJ, which gives a peak-power of over 200 kW.

We propose a new scheme of optical klystron harmonic Free-Electron Laser in this paper. We have analyzed this novel harmonic Free-Electron Laser by using Madey's theorem. Theoretical analysis indicates that the higher harmonic emission power density and gain can be enhanced greatly by using this new structure wiggler. Thus it is possible that the Free- Electron Laser can operate on higher harmonics and emit shortwavelength.

In order to calculate the distortions induced by the travelling- wave semiconductor laser amplifiers after the multi-channel CATV signals passing through them , the output power Pout of the amplifier can be represented with the Taylor series of the input power Pin. By finding out the solutions to the rate equations of the amplifiers,the analytical expressions of the derivatives, up to the third order, of Pout with respect to Pin have been deduced.

We studied the optical bistability for four-level system with single and triple state typical of organic media. By means of the rate-equation approximation of a densitymatrix method, the state equation of optical bistability was derived. The bistability with absorption or dispersion of single state and triple state is numerically discussed. We analysed the effect of cooperative parameter, atomic and cavity detunins parameter on optical bistability.

The full saturation effects of a bidirectional ring gas laser are studied theoretically. An analytic expression of the laser intensity distribution function at steady state is derived. The auto and cross correlation functions of the steady saute two mode intensities are calculated. Compared with third order laser theory and experimental measurements, excellent agreement between full saturation theory and experimentS is obtained. The third order theory leads relatively large errors.

The chirping characteristics of traveling-wave semiconductor laser amplifiers (TW-SLAs) are analyzed in detail. The chirping compensation of light source chirping and fiber dispersion, using self-phase modulation (SPM) induced by gain saturation in a TW-SLA, is demonstrated theoretically. The possibility of phase compensation is shown in all the cases of different input pulse widths (much shorter, comparable, and far longer than the amplifier carrier lifetime). This feature can be used to achieve energy amplification with phase compensation of weak chirped pulses in long-haul optical communication systems.

By using small-amplitude approximation on continuous wave bsckground, the gain dispersion and two-photon absorption supported small-amplitude dark optical soliton solutions are analytically studied in this paper. Their features of evolution in the various regions in parameter space are discussed. The result shows that the small-amplitude dark solitons are stable in some regions, but are constable in other regions in which the smallamplitude saute of the dark soliton will contains until excessed certain propagating distance.

A theory on the coupling and coherence between resonance modes induced by inhomogeneous medium and gain saturation has been established.

Unstubility and chaos of a detuned homogeneously broadened laser are studied.Under the different conditions, the criterions, when a laser becomes unstable via a Hopf bifurcation and mode hopping, are given, which defines the unstability margin of a laser. Moreover, by numerical simulation, we verify the criterions and find that Lorenz unstability can trigger mode hopping unstubility on certain condition.

The optical absorption of one-dimensional semiconductor in an electromagnetic field is studied involving the direct and indirect transition of electron between the bands and considering the optical absorption of exciton. The absorption coefficient of the onedimensional semiconductor is derived.

An electrically tunable single-mode fiber Bragg reflective filter (FBR) is firstly demonstrated by using a giant magnetostrictive material to which the fiber is embedd in and side-polished. With a reflection bandwidth of about 1.5 nm, our measured tuning range of the FBR filter is 1.3 nm.

In this paper, experimental study on excimer XeCl (308 nm) ultraviolet laser ablation of C60 films and their morphology analysis are reported. A possible mechanism is presented on the basis of the morphology analysis.

The properties of atomic coherent trapping are studied for the Raman-type system driven by a two-mode quantized field. The influences of the parameters describing the atom-field coupling character on the coherent trapping are analyzed. And it is verified that the atom can be trapped by the two-mode SU(2) coherent field under ceriumconditions.

This paper discusses the rotating cone-glass shearing camera used for dynamic measurement of slope and curvature. The whole process of slope and curvature can be recorded on a single specklegram.

The phase- shift technique is adopted to the conventional shadow moire topography to improve the measuring sensitivity and compunctional processing. The generation and error of phase-shift and experimental results are presented.

Large-area, free-standing X-ray diffraction gratings are of great importance in X-ray optics. Experimental tests on the large-area, free-standing transmission gratings made by Hefei National Synchrotron Radiation Laboratory manifest their success in manufacturing. This kind of gratings can be used for X- ray meaurements and applications in various fields from laboratory X-ray sources to astronomy.

In this paper, we report the first observation of continuum emission band of 225～235 nm with a maximum Peak at about 230 nm of Hg2 excimer in high-pressure mercury arc lamp. Comparing the computer- simulated emission spectra with the experimental results, we identify that this 230 nm continuum band is ascribed to the transition of GO state to XO state of Hg2 excimer, and give the fitting value of equilibrium internuclear separations difference Re"-Re'=0.085±0.002 nm.

The rotational excitation spectra of 4d gerade Rydberg state of bromine molecule in the region of 68800-69600 cm-1 have been recorder by (2+1) multiphoton ionization. The rotational constant has been obtained from the analysis of the spectra as B81-81=0. 08688. The electron angular momentum is assigned to be Ω=1.

The nuclear impaction spectra of neon, helium-neon and helium-neon-argon mixtures at different compositions and pressures are measured. Based on themeasurement, the influence of pressure of neon, helium and argon on the intensity of Ne 585.2 nm and the efficiency of filling of ten 2P levels of Ne is summarized by calculating the radiation rate I, the relative populations N and the filling rate W of ten 2P levels of Ne.