The features of Fresnel diffraction was fully characterized for the serratedaperture in this paper, we have proposed and demonstrated that modulated sinusoidalserrated apperture can effectively suppress the near-axis intensity ripples for a large scaleof Fresnel numbers. The design procedure was also given for its application in the highpowers laser systems.

real color rainbow hologram; image composition

An atomic force microscope based on the optical level detection method hasbeen developed and atomic resolution is achieved. The scanning range is 7 Urn × 7 μm.images of mica. optical grating and compact stamper are shown. In this paper thetheory,construunction and experiment results are described.

This paper describes the Performance of a prelase Q-switched singlelongitudinal mode Nd:YAG laser which was end pumped by a diode laser array withoutput of CW 1.5 W. This oscillator provides single longitudinal mode Q-switched pulsewith instability less than ±1% at 100 nsec duration and the linewidth less than 25 MHz.

Thermal distortion of ZnSe output couplers with high reflectot (HR) coatingSin high POwer transverse flow CO2 lasers is studied theoretically and experimentally.Under the condition of reasonable approximation, approximate formulae of temperaturedistribution and thermal distortion of the ZnSe output couplers are derived. The theorycoincides well with the experimental results.

In this paper we investigate the effect of fullerenes inside a free running Nd:YAG laser cavity. It is found that the strong nonlinear absorption of fullerene moleculescan smooth the self mode-locking pluse series in the nanosecond time region, which isestimated to be a result of the two-photon absorption of fullerenes.

Two methods and their experiments for laser beam autocollimation areintroduced, the phase step method is based on spatially modulating the incident laser beamby a phase step plate3 and the phase dot method, by passing through the phase dot, thediffraction phenomena of both incident beam and reflected beam are utilized. Theintensity distribution modulated by both phase shifting plate are analyzed based onFraunhofer scalar diffraction theory. The experimental results are presented as well.

Concentration effect on the ultraviolet absorption spectrum, visible blueemndssion spectra and the corresPOndent excitation spectra of Ti: Al2O3 crystal had beeninvestigated. At liquid nitrogen temperature,the brosd 420 urn blue emission bandsplitted intO 330 um, 420 um, 460 um and 560 um sub-bands, which were attributedrespectively to the F+ and F centers of the host Al2O3 lattice and Ti4+ related chargetransfer transitions among ligsnds and metal ions. Concentration quenching of the blueemission at room temperature was the co-effect of the emission quenching related to Ti4+ ions and the increasing of the blue-green band absorption corresponding to Ti3+ ions. Absorption band peaked at 266 nm in the ultraviolet absorption spectrum was constructed by charge transfer transtions of Ti4+ and Fe3+ ions in Ti:Al2O3 crystal.

The Raman soliton self-frequency shift in soliton fiber is investigated by meansof analyzing Perturbatively quasinonlinear Schrodinger equation including fiber loss andRaman delayed nonlinear effect.It is found that the self-frequency shift in soliton fiber ismuch small comparing to that in conventional fiber, and it can be controlled by adjustingthe fiber structure Parameters.

In Ce:Mn:LiNbO3 crystal, the two-beam coupling exponential gaincoefficient increases sharply along with the decrease of the thickness of the crystal sheet.INcreasing beam diameter of the pump light, the angle range 2θ of gain Г,may beextended.Nearby 55 ℃, 71 ℃ and 110℃, three extrordinary peaks present. ThesePhenomena are studued in this poper.

Mathematic relations between system characteristics, materials characteristicsand read/write condition are established for holographic grating spectral hole-burningtechnology. Optimal parameter space of material characteristics is achieved bAsed oncomputer simulation analysis.The resultS show that holographic grating spectral holeburning technology will greatly decrease the requirements of system characteristicsimposing on material characteristics, which will offer new theoretical guidance for thestudy of hole-burning material.

It is pointed out in this poper that the modulation of optical confinement factorin index coupled DFB lasers can give rise to the gum coupling effect.This effect is smallnear threshold region, but it increases when output POwer increases. The influence of thisgain coupling effect in λ/4 Phase Shifted DFB lasers on threShold gum and frequency shiftis in some way like spatial hole burning.The quantum size effeCt has little influence onthis gain coupling effect. Because the spatial hole burning is much small in MQW lasers, the influence of this gain coupling effect on the threshold gain and frequency shift in MQW lasers will be obliviously.

By means of Placzek Model and using the finest experimental values so far ofRaman differential cross sections at 488 nm as standards, we have calculated the valuesof Raman differential cross sections of gases at 308 nm. After compering the resultS tosome exiSting experimental and theoretical results in H2 at 308 nm, we found that theresultS show good agreements with the existing results.

laser pulses with a duration of 30～300 ps is produced by a optical freeinduction decay (OFID) laser system with a single mode TEA CO2 laser preionized by anovel surface corona discharge, and with plasma shutter and hot absorber cell.

Simulation of X-ray laser has been Performed for Li-like silicon, pumped bythe 116 ps laSer pulse with intensity of 5.4 ×1012 W/cm2 and wavelength of 1. 06 μm.The results have been compered with experiment.

Experimental resultS of a laser diode array (LDA)-pumped intracavity doubledNd: BGO laser are reported in this peper for the first time. By use of a intfacavity Loytfilter foamed with a Brewster plate and a birefringent KTP crystal, we obtained 3.5 mW stable, single-longitudinal-mode green output at 500 mW LDA pum ping power.

The temperature dependence of the alexandritC laser's characteristics isanalysed theoretically and verified experimentally.It shows that the gain and pumpingefficiency of the alexandrite laser will increase with the rising of temperature, while thelaser threshold decreases.

It is theoretically demonstrated that a new kind of soliton, having the waveform of sech1/2(x),can propagste in a single mode optical fiber. For the conventional fiber, itS temPOral width is about onenanosecond when peak input POwer is about I Watt at the wavelength 1.3 micron.

The influences of Kerr effect, diffraction and dispersion effect on thepropagtion properties of laser pulse in a normally dispersive 2+ 1 dimensional media arediscussed.The impacts of initial pulse width, beam width and chirp on the pulse widthcompression are studied by using numerical method.

In this paper the relations between the amplitudes of electromagnetic waves propagating in multilayer media and those of incident waves on surface are deduced. And a generating function by which the transmitted waves in every layer can be generated isintroduced.

The Fokker-Planck equation is solved by using the propagstor method. TheGreen function is calculated by using the local harmonic approximation method. Thepaper also discusses the applications in the quantum optics.

The emission spectra of Eu3+: Gd2O2S has been measured at room temperatureunder pressure up to 15 GPa. The pressure dependence of levels and crystal field forcentral ions was studied by data fit.

A systematic study of the spectra of neon by nuclear impaction is reported. Asingle photon counting system designed and set up by ourself has been used to measure thespectra of neon excited by alpha particles emitted from 238Pn. Thirty three of neontransition lines are identified, two of them, i. e. 664.0 nm and 711.6 nm are probablydue to the transitions 3s4-3p4 and 4d2-2pl respectively, which has not been observedin the neon spectra by electronic impaction. Based on the Atomic and Molecular Reaction statics, the so-called dissociative recombination inversion mechanism in nuclear pumped laser is proposed and fairly proved by our works for the first time.

The excitation and emission spectra of Eu3+ compounds (Eu(TTA)3phen andEuCl3.6H2O)are studied with the laser-excited ion(Eu3+) and high detection sensitivitytime-resolved luminescence technique. The experimental results demonstrate that thechanges of excitation spectra(especially for the 7F0→5D0 hypersensitive transition ) ofEu3+ are sensitive to the ligands. The ratios of the oscillator strength of hypersebSitivetransition (7F0→5D0) to that of magnetic dipole transition (7F1→5D0 ) from Eu3+ ionsin EuCl3·6H2O and Eu (TTA)3phen crystals are 0.031 and 0.067 transition, respectively. The splittings of 7F1→5D0 magnetic dipole transition, which depend on the strength and symmetry of the crystal field, are also measured. Under the resonant and nonresonant pulse excitations for 7F0→5D0 transition with a time duration of about 10 picoseconds, the immediately emission of 5D0→7F2,3,4 can be observed. This implies that the population time of 5D0 energy level is less than 10 picosecons under the laser-excited Eu3+. The experimental result also shows that there is a broad nonexponential decay fluorescence band with time constant from picoseconds to nanoseconds covering the spectral region of 5D0→7F2,3,4 transitions in Er (TTA)3 phen crystal.

The energy transfer reaction of metastable He (23S) with CH3CN has beeninvestigated. Near-violet emission spectra of CN (B-X) and CH (A-X) wereobserved. Based uPOn the spectra of excited fragment we estimated the formation rateconstant and vibrational POpulation of CN (B). The reaction mechanism were alsodiscussed.

Comparison between spectra from the facet of a semiconductor laser before andafter AR coated under the same bias condition has led to the establishment of the variationcurve of the facet reflectivity vs. the wavelength.,This method is applicable to a certainwavelength range, and overcomes the difficulty encountered when Kaminow's methodis implemented to determine the very low reflectivity of the diode with both facetS ARcoated.As a result, a reflectivity of less than 8×10-5 at the second coated facet has been measured.