This paper summarizedthe method of M2 factor measuring and data processing for quasi-gaussdistribution beams and measured the M2 factor of the 5.4 TW/46 fs laser system.The experiment setup and the steps of amending the beam quality are briefly introduced.The result was reported with some analysis about the performance of this system.

Based on original ideaabout monolithic integration of the SLD (superluminescent diode) with SOA (semiconductoroptical amplifier), the axis of current injection region was tilted by 6° with respect tothe output facet normal, by this means, 1.5 μm InGaAsP/InP integrated superluminescent light source with tiltedstructure has been fabricated. High superluminescent power of 38 mW was obtained at lowerpumping level by co-operation of the two sections. The spectral full width at half maximum(FWHM) is 16 nm, and the FWHM far field pattern (FFP) parallel and perpendicular to thejunction plane are 15° and 64°, respectively. A new phenomenon was discovered, in whichthe lasing action was suppressed by pumping the SLD section of the integrated deviceproperly.

This paper presents amethod to detect the displacement of the interference stripe in LD interference field soas to get the information of LD frequency fluctuation. The Michelson interferenceapparatus is chosen in the laboratorial device. CCD is used to sense the displacementsignal of interfernce stripe in the interference field. After corresponding circuitprocessing, the useful signal then is input to a computer. At last, the frequencyfluctuation of LD can be detected.

A novel taper couplerwas fabricated. The transmission loss of hollow-core optical fibers with the taper couplercan be reduced to about 50 percent.

Laser basedphotoacoustic technique applied to trace gas measurement has proved to be a high sensitivemethod. The implementation of the computer control and data processing system makes themulti-component analysis and long-time continuous measurement of the photoacousticspectrometer available, and it also increases the sensitivity and reliability of thespectrometer. System performance measurement shows that the detect limit for ethyleneconcentration of 14×10-12 and the accuracy of 2% are reachable. As anapplication of the system to biological study, an experiment on monitoring of the ethyleneproduction from apple and cherry tomato fruit in anoxia and post anoxia condition has beencarried out.

In this paper, a new method is proposed to enlarge the measurement range of the LD-SPM interferometer with a photothermal wavelength modulation. Using this method, the measurement range is enlarged from half wavelength to 125.56 μm and the measurement accuracy is 1.2 nm. The possibility of further enlarging the measurement range is discussed.

The effects of spatialcurvature radius on the laser cutting quality indexes of pipe with spiral cutting patternsuch as the top kerf width, the extent of heat-affected zone (HAZ), the cut surfaceroughness Rz, the microhardness (HV0.1), the half-squareness were investigated.The results show that the values of the kerf width on the upper surface, thehalf-squareness, and the HAZ increase with the increase of spatial curvature radius exceptfor the values of the cut surface roughness Rz as the diameter of pipe remains unchangedand the pitch increases. The main reason is the heat accumulation and preheating effects.

In this paper, a novel method for measuring the deformation of dragonfly wing based on comb-fringe projection is introduced as well as relative experiments. The result shows that there is concernful elastic deformation on the flapping wing.

A thermo-elasto-opticaldistortion model for the main amplifier of SG-Ⅲ prototype is presented in this paper, which consists ofthree modules, i.e., modules of heat transfer, thermo-elastics and optics. With thismodel, the residual thermal distortion of the main amplifier of SG-Ⅲprototype is investigated. The calculatingresults indicate that, with an optimization thermal recovery, the thermal gradient and theaverage temperature of the slab can be reduced to an acceptable value. The residualthermo-optical distortions can meet the design requirements. Additionally, a quantitativerelation between the thermal distortion and the linear thermal expansion coefficient ofthe laser gain medium have been also obtained.

The stable mode-lockingoperation of a pulsed Nd:YAG laser was achieved by inserting a LiF:F-2 crystal into the critical stableplane-concave resonator. This paper analyzed the action of nonlinear absorption of LiF:F-2 inmode-locking progress, and calculated the changes of stable range of the resonator and thelaser mode sizes, due to self-focus of Nd:YAG. The theoretical and experimental results showed that the Kerrlens effect was the key factor of mode-locking operation for the Nd:YAG laser.

Fiber-gratingadditive-pulse mode-locked fiber laser is analyzed in detail. The oscillation conditionsfor the additive-pulse mode-locked laser was found, it was showed that after reachingstable, the laser′sgain, the loss, the coupling efficiency between the two cavities, and the oscillationwavelength will construct an approximate isosceles triangle on the complex plane. Furtheranalysis of the gain of the laser on the starting stage showed that the gain at the maincavity is unsymmetrical with the central wavelength of fiber gratings, which leads theunsymmetry of the spectrum of the output laser pulses. It was also found that in order torealize the laser oscillation the differences between the two cavities′ nominal length should beadjusted at a certain value because of the light penetration into the fiber gratings.

A new connecting way wasdone in Yb3+-doped fiber laser, in which a Yb3+-doped fiber waslocated at an unpumped place. Narrow-linewidth lasing was obtained by using of a bandpassfilter and the unpumped Yb3+-doped fiber acted as saturable absorber. Thelinewidth of output laser was less than 0.07 nm. The effect of unpumped dopant fibersaturable absorber in Yb3+-doped narrow-linewidth fiber laser was researched indetail.

The relation between CWDF/HF chemical laser performance and the flowfield parameters in F&D2/H2reacting zone has been studied based on the original formula of gain coefficient,outputpower and laser efficiency. The relation is proved by simulation results and others′ experiments and provides acriterion to optimize the nozzle design and CW DF/HF chemical laser performance.

In anomalous dispersivefiber, fundamental soliton pules have the desirable property i.e. their shape and pulsewidth are invariant during propagation along the fiber. In this paper, a new method tocompress fundamental soliton pulses in the anomalous dispersion regime throughcross-phase-modulation for pump pulse and soliton pulse is proposed. Two nonlinear coupledequations were established to describe the propagation of pulses in the fiber and solvednumerically. It is found that the fundamental soliton can be compressed by using themethod of the cross-phase modulation and exists an optimum value of fiber length in thecompression. It is also found that the pump pulse power, pump frequency chirp and variouspulse widths have great effects on soliton pulse compression. In order to obtain largecompression factor, pump pulses with negative chirp and narrow pulse-width are desirableselected.

Carbon cluster anionsare generated by a standard laser vaporization/pulsed molecular beam scheme and detectedwith a time of flight mass spectrometer. Through the study of mass spectra, it is revealedthat the structure of most carbon clusters transforms from rings to cages as the clustersize grows up. The discussion is focussed on how the intensities of the vaporizing laserand carrier gas influence the characteristics of the C-n massspectra.

In this paper, theimpact of the orders of fractional corrrelator on the energy distribution of thecorrelation plane is analyzed theoretically, and then the performance of fractionalcorrelator for scale distortion-invariant pattern recognition is discussed deeply bynumerical method based on the matched-filtering configuration. A comparison is made withthe conventional correlation that shows the fractional correlation possesses more powerfulcapability of scale distortion-invariant pattern recognition than that of the conventionalcorrelation.

A new type of leakyannular pupil filter is designed to achieve 3-D superresolution in this paper. Bothtransversal and axial property of this filter are analysed and a simulation example filteris provided which improves 3-D resolution of the imaging system when it is combined withconventional imaging system. Unfortunately, the sidelobe of axial intensity distributionis too high in conventional system. With applying this pupil filter to confocal scanningmicroscope, a good 3-D superresolution is achieved.

The influence ofacoustic wave attenuation on the properties of fiber AOTF is studied and a simple methodto determine the acoustic wave attenuation by measuring the AO mode coupling effeciency isproposed. It is found that the acoustic wave′s attenuation will reduce the efficiency of AO mode coupling andbroaden the bandwidth of fiber AOTF. The increased bandwidth is in proportional to thesquare of the acoustic wave attenuation coeffecient.

The absorption andfluorescent spectra and fluorescent lifetime of Yb3+ and Er3+co-doped phosphate glass were measured. Some basic properties of spectroscopic propertiessuch as absorption cross section and stimulated emission cross section have beencalculated. The effect of P2O5 and Yb2O3concentrations, alkali metal oxides, alkaline earth metal oxides and OH- on spectroscopicproperties of phosphate erbium glasses have been discussed. The Yb3+ and Er3+co-doped phosphate erbium glass with fluorescent lifetime of 7.5 ms and stimulatedemission cross section of 0.8×10-20 cm2 has been achieved inpresent work. This provides good basis for the future laser experiments.

By using degeneratefour-wave mixing, the third-order nonlinear optical properties of nc-Si:H thin films were investigated.The phase conjugation signal was observed, and the third-order nonlinear susceptibilitiesat 589 nm for the volume fraction XC1=15% and XC2=30% of thecrystalline in the samples are χ1(3)=3.8×10-6 esu and χ2(3)=4.3×10-7esu, respectively. The nonlinear machanism of the material was discussed.

The detail experimentalstudy of phase modulation for Stimulated Brillouin Scattering (SBS) suppression in opticalfiber AM-CATV externally modulated transmitter is presented in this paper. Theexperimental data show that the improvement of SBS threshold is dependent of the number ofSBS suppression source and the phase modulation index, and independent of the frequency ofSBS suppression signal. The experiments also show that single signal phase modulation canimprove the SBS threshold to 13 dBm and two signal phase modulation can improves the SBSthreshold to 18 dBm or above. It is also demonstrated in this paper that the phasemodulation has no influence on the nonlinearity in optical fiber AM-CATV externallymodulated transmission system.

Molecular structure andoptical nonlinearity in interleaving hemicyanine/arachidic acid or cadmium arachidatemultilayers, and Z-type pure hemicyanine multilayers were investigated as a function ofthe temperature by means of second harmonic generation (SHG) and linear absorption. TheSHG intensity shows a maximum at about 45℃ in the multilayers. An inflection was observed in the temperaturedependence of SHG intensity in the interleaving hemicyanine/arachidic acid andhemicyanine/cadmium arachidate multilayers, and was attributed to melting of arachidicacid or cadmium arachidate. The absorption spectra show that the molecules in themultilayers formed H-aggregates which could be dissociated by heating.

The laser beam passingthrough the focusing systems gets an facula,which consists of main spot and sidelobe onthe focus plane. In order to eliminate the sidelobe, a method of obstructing aperture ofthe focusing optical system is advanced. The experiment and the theory show that thesidelobe is reduced.