In this paper the development of laser and crystal Yb:YAG is reviewed. The char- acteristics of Yb3+ ion lasing are summarized. And especially, some important experimental results on Yb:YAG, including crystal growth, defects, the properties of spectra and laser, are presented. The main problems on the development of this kind of high power laser crystal are also indicated.

In this paper we report novel experimental results of the erbium-doped-fiber ring resonator behaviors operating near threshold. The reaction of threshold on linewidth of ring's output light is pointed out. This provides a new auxiliary method to determine the threshold. The limits of finesse are analyzed. We also propose a new subsidiary method for finesse measurement based on self-homodyne by using of resonating of the intra-cavity amplified spontaneous emission (ASE) light, without external light source.

The shifts of zero dispersion wavelength for a few of impure fiber due to the Change of refractive index of fiber have been researched. A numerical analysis method used for calculating phase matching with the parametric effect is put forward, the phase mismatching from the material and waveguide dispersion of the fiber in the parametric effect is calculated by the numeric method and the spatial curvature surfaces of phase mismatching Changed with both pump light wavelength and frequency shift between the pump and signal light are given. The results show that there is the biggest flequency shift meeting the condition of the phase matching near the zero dispersion position and this rule doesn't changed with the shift of zero dispersion.

We propose a new method to fabricate a photorefractive Dammann grating in this pa- per. Dammann grating is fabricated by photorefractive effect in LiNbO3:Fe crystal using imaging method. The photorefractive Dammann grating has not only the advantage of a conventional Dammmann grating, moreover, the method is real time and very simple, and the crystal can be used recycled. This method can be widely used in optical information processing and integrated optics.

This paper describes the design of a microcomputer controlling system for high power excimer Iaser, which is suitable for the measurement of characteristics of excimer laser when it works normally This device has the features of easy to operate, low cost and small error. Measurements show that the device is stable and practicable.

The absorption spectra in a range of VIS to NIR and the stretching infrared spectra of OH-radical in Ti-doped a-Al2O3 crystal are measured in a number of samples. The obtained experimental data support that the residual infrared absorption is really due to Ti3+-Ti4+ pairs rather than structure defects with adjacent Ti4+ ions in the crystal. We conclude that Ti3+-Ti4+ pairs probably locate at phase boundary between matrix and heterogeneous phase (TiO2) or in body of heterogeneous phase, i.e., the residual infrared absorption is absorption of the Ti3+ ions located at the phase boundary or in body of heterogeneous phase.

It is demonstrated that a nonlinear Schrodinger equation with certain nonlinearities allows for an existence of multistable singular solitons (i.e. singular solutions with the same carried power but different propagation parameters). Using a paticular nonlinearities (the "linear smooth step"model) as an illustrative example, the switching of bistable solitons states of the highly-nonlinear (generlised) Schrodinger equation is simulated.

Based on the theory of SBS, its optical parametric generator and amplifier are pre- sented. the influence of phase mismatch on the corresponding phase conjugation reflectivity. pump threshold power and magniflcation times are also analyzed. which will provide theoretical reference for the further improvement of phase conjugation technology by using the amplifier.

In this paper, the atomic squeezing effects in the two-photon process with two-level atomic mixed-state are studied by means of the time-evolution operator method and numerical calculation. The results show that the squeezing properity of the atom do depend greatly on the atomic initial mixed-state, and the atomic squeezing effect is displayed periodically as 0.85 < S<1;with the increasing of the mixing extent of the atomic initial state, the characteristics of atom is getting far from squeezing state.

The entropy properties of the [1] type three-level atom in uncoupled two modes are studies. The influences of the parameters of the field state, atom-field coupling constants and the initial atomic state on the atomic entropy are discussed.

The mesoscopic capacitor coupled circuit of 3 meshes can be considered as the canon- ical ensemble. It gets at quantum fluctuations of both charge and magnetic flux in the coupled circuit at a finite temperature by calculating the density matrix of the canonical ensemble. Our results show that quantum fluctuations of both charge and magnetic flux depend on the tem- perature. With high frequency, charge fluctuation, which are similar to the situation of low temperature, show typical quantum noise, and it is impertinent to temperature. But magnetic flux fluctuation not only is quantum fluctuation of zero point temperature, also is always con- nected with temperature. At absolute zero point temperature, the uncertainty relation of both charge and magnetic flux in the input mesh or in the output mesh is constant.

Starting from the physical mechanism of the generation of the resistance or the interaction of electrons with the lattices, a new quantization method is given for the RLC electric circuit. And the quantum fluctuations are computed.

In this paper, the aerospace SEP(Single Event Phenomenon) fault injection system based on inserting fault both in the memory and through the bus is presented. The structure and functions of FIS(fault injection system) are firstly introduced. On the basis of expansibility and universality, the study is concentrated on the key implementation technology in fault insertion unit. The practical results show that the FIS is low cost, high universality, fully dynadrically and real-timely inserted.

We examined the surface property of nanometer Si3N4 quantum dots, before and after N+ ion injection. XPS measurement revealed that there were more oxygen existing on the surface comparing to that in the bluk. After ion injection, there were more oxygen existing on the suface, furthermore adsobing oxygen converted to binding oxygen. The exciton effect in the interfacial layer played role in enhancing blue-light emission.

By analyzing HB-LED model about electrical inject, optical output and calculating the distributing of electrical density photon output coupling efficiency at different top layer in HB-LED, we found the thicker of top layer and bottom layer, the easier for electrical spread and optical output. The calculating result showed that the thickness of top layer and bottom layer should be 49-98μm and 148μm, respectively The maximal external quantum efficiency of these types of LED is 12.05% and 20.12%.

Electromodulation transmittance spectroscopy of CdS0.1Se0.9 nanocrystals embeded in the glass matrix is measured at room-temperature. Stronger electro-optical signals (10-4 - 10-3) are observed in both resonant and nonresonant regimes. These are some experimental results in resonant regime. The peak positions of electro-optical signals shift to higher energy direction when the nanocrystal size decreases;the line-shape of spectra for the same sample is independent of the external electric field strength;there are linear relationship between the signal magnitudes scale and the square of applied field strength, which indicates that the electro-optical effect of nanocrystals is the Kerr effect and the nanocrystals have the third-order nonlinear optical sus- ceptibility X(3);the signal magnitudes decrease when the modulation frequencies increase. The physical mechanism of resonant electro-optical effect is consistent with quantum-confined Stark effect. The oscillatory electro-optical signals in nonresonant regime are observed at frequency of 230Hz.The magnitudes of nonresonant electro-optical signal tend to enhangce with the increasing of the external electric field strength.The origin of nonresonant electro-optical effect is decreibed with "dielectric confinement"effect.

The paper introduces how to use numeric approach calibrating parameters of laser triangulation of long displacement. The method of numeric approach based on the least square method is highly precise in calibrating the parameters.