In this paper 532 nm pulse imaging lidar experimental equipment was introduced. Both the effects of background noise and the signal to noise of 532 nm pulse lidar system under different conditions were analyzed. The relationship of distance, pulse energy and visibility under narrow view angle was researched by experiments.

This paper introduced the main characterstics and relative development process of the thin films constructions of semiconductor saturable absorber mirror, which supported the self starting mechanism in the femtosecond lasers. The great emphases were focused on the contribution of the electrical fields of the thin films constructions and the affection due to the reflectivity and the bandwidth. Also the comparison of reflectivity for the three different constructions in semiconductor saturable absorber mirror was made.

Based on rigorous coupled wave theory, the relationship between diffraction property of rectangular phase gratings in resonant region and grating period, duty cycle, thickness is analyzed. An achromatic quarter wave grating for 400～800 nm is designed. In the broadband, the grating has smooth efficiency and phase retardation. Specially, the phase retardation could maintain about 90°, and the maximum retardation deviation is less than 9%. Its performance is even better than some normal binary achromatic wave plates. With the analysis of fabrication error, it is noted that thickness error and duty cycle error affect the grating′s performance greatly.

Fourier transform spectrometer (FTS) modulated by means of rotary grating is developed in this paper. The grating simultaneously acts as a beam splitter and a heterodyne modulator. Three shemes to separate the light beams are analyzed. Three lasers with the wavelength of 670 nm, 633 nm and 532 nm respectively have been adopted to implement the measurement of spectrum. Experimental results show that this FTS takes advantage of favorable stability and strong ability of anti disturbance. The sensitivity of meausurement has been improved by 20 times with the modulation method. It is expected to be effective particularty in the domain of weak signal measurement and near infrared region.

The polarization mode dispersion (PMD) of fiber Bragg gratings (FBG) is detailedly studied. Theoretic analysis and experimental measurement are carried out on FBG. Birefringence of UV written gratings mainly comes from the asymmetrical absorption of photosensitive fiber, or exponential absorption. Considering the influence of UV induced fiber birefringence, gratings chromatic dispersion on the PMD of FBG, the model of FBG's PMD is founded. Numerical calculation is concident with the experimental measurement. The dispersion of FBG can effect PMD.

A Galerkin′s method based numerical procedure is used to design photonic crystal fibers with zero dispersion wavelength at 800 nm. High accuracy is maintained by using a large enough area of calculation and sufficient basis functions. The zero dispersion wavelength is designed to be the operating wavelength of the widely used Ti∶sapphire femtosecond lasers, holding much promise for the applications of femtosecond laser.

A new method to etching emitter region groove approach of magnetic sensitive transistor was proposed by combine laser with MEMS technique. The results from the experiment show that new method can etch emitter region groove approach of magnetic sensitive transistor with high quality and high etching rates of Si, and process Si of without mask.

This paper reported a set of metal atom evaporation device of linear source. The device is composed of the following parts: stainless steel vacuum evaporation cavity, vacuum attaining system, electron gun, crucible, uniform magnetic field, push and pull inner worktable, water cooling system, power supply, measure instrument and control circuit. The device has achieved its primary design targets by several test runs after installing and debugging. The vacuum degree is above 3×10 -3 Pa. The superficial melt area reaches to 22 mm×4 mm to gadolinium metallic material. Many experiments such as the evaporation by the electron gun, ions extraction can be carried out with this device.

This paper describes the method and processing parameters of laser welding of 8 mm thick stainless steel with high power Nd∶YAG CW laser. The experiments show good welding quality can be achieved although there is gap and step between the two welding parts. The measurement result illustrates that the hardness of welding seam is twice as that of base material.

Experiments of laser milling were done on Al 2O 3 ceramics with Nd∶YAG laser. The specialiments on the accounts of laser milling and milling surface quality with different parameters were studied systematically, and experiments of different shapes were also researched with optimized processes.

Noticing that strong exothermic reaction due to large negative enthalpy of mixing can occur among major components of bulk metallic glass forming alloy systems, a new technique to fabricate an amorphous based composite material using laser induced self propagating reaction synthesis (LSRS) is developed. The LSRS for Zr Al Ni Cu alloy system shows that the products mainly consist of amorphous, Zr 3Al 2 and Zr 2Cu phases. With increasing of impure (Zr,C) in raw powder mixtures, the amount of amorphous phase in products decreases, while microhardness and wear resistance of products increase.

By analyzing the 1st order statistic specialty of the co coherence function of Gauss local field and Airy signal field, it gives the matching condition between the amplitudes, phases, and wave vectors of the signal beam and the local beam in CO 2 laser pulse heterodyne detection. In theory, the maximum of the heterodyne quantum efficiency is 0.82. In the condition of off focus, e.g. with spherical aberration, the phase difference between signal beam and local beam is mainly decided by the curvature of the Gauss local field which would lead to the reduction of the heterodyne quantum efficiency.

Numerical calculations about the gain and ASE intensity of a dye laser amplifier are preformed in two cases: the input laser flux is far smaller or larger than effective saturation flux. The influences of ASE coefficient and reflective coefficient of dye cells on the gain and ASE intensity are discussed too. These results are used to discuss the optimizing design of a CW laser seeded multistage dye laser amplifier.

The kinetics model of Ar + 2 ionic excimer pumped by electron beam is built. The reactions on energy deposition of electron beam and formation of Ar + 2 ionic excimer are found. The reaction rate equations are given. The equations are calculated numerically and the relation between number density of Ar + 2 ionic excimer and time is obtained. With the calculation results of number density, the small signal gain is calculated. Experimental results are compared with the theoretical results. And it is proved that the 240 nm spectrum in the third continuum originates from the transition of Ar + 2 ionic excimer.

An output pulse energy of 40 mJ, repetition rate of 20 Hz at 1.57 μm with the beam divergence of 4 mrad was obtained in an OPO by using VRM unstable resonator.

Computer generated hologram of fractional Fourier transform is presented. With fast arithmetic of fractional Fourier transform and Lohmann Ⅲ detour phase coding method, fractional Fourier transform CGH in different fractional orders of one object are programmed and fabricated. These holograms are reconstructed with Lohmann Ⅰ fractional Fourier transform optical system and a clear images are obtained. The changing rule of FRTCGH and reconstructed images is analyzed as fractional orders change. The relationship between fractional Fourier transform CGH and Fresnel CGH is discussed.

A numerical simulation study on the field of Nd 3+ concentration in the melt and the crystal by using FDM (finite differential method) during the growth of Nd∶YAG crystal by Cz (Czochralski) method was reported. At first, the mathematical model of the growth of Nd∶YAG crystal was given, then the equations with no dimensions were given. Finally, the boundary condition was given and the equations were solved by FDM. The simulation program was given by above method, and then the change of the field of the Nd 3+ concentration in the melt and the crystal was described by simulation program. The effect of processing conditions on the above field in the melt was analyzed.

Angle tuning curves and the ranges of wavelength were obtained by using Sellmeier equations and numerical simulation of type Ⅰ and type Ⅱ on crystal CsLiB 6O 10 , compared with those of β BaB 2O 4. And it can be seen that CsLiB 6O 10 is an excellent nonlinear crystal in ultraviolet wave band.

The recordable disks using TeO x thin films as the recording medium and the erasable disks using Ag In Sb Te O thin films as the recording medium were fabricated by the methods of vacuum evaporation and by the method of sputtering, respectively. Dynamic recording properties of the two kinds of disks at 514 5 nm were reported. The carrier to noise ratio (CNR) of the recordable disk could reach about 30 dB at 514 5 nm and 41 dB at 780 nm ; that of the erasable disk could reach about 25 dB at 514 5 nm and 38dB at 780 nm. The reasons which caused the low CNR were discussed. The two kinds of films had the potential for using as blue green short wavelength high density optical storage media.

In this paper, an in situ technique was used to determine the laser absorptivity of solid and liquid surfaces of Al alloys. The experimental results show that the surface condition of the sample is the most important factor affecting the laser absorptivity. Usually, the absorptivity increases a little with the increase in laser power. But if the laser power is too high, the absorptivity of blacked samples will be decreased because of burnout of blacking layer. When melting pool emerges on the surface of sample, the measured laser absorptivity is an ensemble average value for liquid and solid zones within the area of laser spot, and the real absorptivity of liquid surface will be determined by using a method combining experiment measurement and numerical simulation. It is also shown by the results that if the incident angle of laser beam is in a range from 0° to 45°, the absorptivity increases linearly with increasing the angle, whatever the surface of specimen is in a state of solid or liquid. The data processing procedure was also improved in this paper. The complex curvilinear equation was replaced by a linear equation and the experimental data were dealt with using linear regression method.

In this paper, the expression formula for the total input electrical field of optical receiver in DWDM systems in the case of existence of optical noise and crosstalk, is deduced. The problem of physical coherence and digital logical correlation is stated in detail. The effect of optical extinction ratio for both signal and crosstalk on the system BER performance is calculated, as the background BER for the case of 10 -9 due to optical noise only and optimal decision level are assumed. It is found that the extinction ratio is about 8～12 dB, while the system BER performance is optimal.

(F,K,1) optical orthogonal codes (OOC's) are the best address codes applied to optical code division multiple access (OCDMA) communication systems. But the construction of the maximal number of the codes, that is the construction of an optimal (F,K,1) OOC's, is very difficult. An algorithm of construction of the OOC's and a method of computer aided design are presented, by which desired optimal (F,K,1) OOC's can be easily constructed.

In this paper, a method evaluating small signal gain spectrum of optical fiber amplifier only using a small power broadband light source was proposed. The coincidence between numerical simulation and experimental results shows that the method was feasible and it had the advantage of simpleness, convenience and easy operation.