The theoretical analysis of the diffraction of Fresnel straight-edge is presented in this paper by the boundary wave approach. The field distributions given by Kirchhoff theory and Rayleigh-Sommerfield theory are studied respectively, and further comparisons with the exact electromagnetic theory are also given. The results show that excellent agreements between them are achieved and the boundary wave approach has the characters of vividly physical view and directly calculation.

Based on the theoretical analysis, the transmission spectrum of a broadband fiber Bragg grating (FBG) have been measured by applying a passive wavelength demodulation system , in which a fiber Bragg grating wavelength scanning laser source is used. The FWHM and the peak reflectivity of the FBG to be measured is 0.48～nm and 94%, respectivly. The experiment result is in good agreement with that measured by an optical spectrum analyzer, with experimental error less than 5%.

The coupling coefficient between two parallel chiral optical fibers immersed in the chiral medium has been numerically computed and discussed in detail. The curves of coupling coefficient's variation with chirality parameters, relative permittivities, normalized frequency and separation has been given.

The complex Hamiltonian of the RLC circuit with a source is analysed. The quantwn fluctuations of the charge and current of the RLC circuit with source is evaluated in excitation state of squeezed vacuum state, and the results are discussed.

In this paper, the orthogonal q coherent state is constructed, its quantum statistic properties such as squeezing property, antibunching effect are studied, the effects of variable q on quantum statistic properties are studied by making use of numerical calculation.

We studied the Wehrl's entropy and Shannon's entropy for superposition coherent states and discussed the relations. It is shown that the entropies are dependent on the superposition coefficient. We point out that the superposition coefficient has great effects on the Shannon's entropy.

In this paper we shall demonstrate the use of intermixing inmodify of GaAs/AlGaAs quantum-well. The paper shows that proton implantation can achievelarge energy shifts after standard annealing procedures. The PL and photoresponse spectrumwere measured as a function of ion dose in the range 5×1014/cm-2 to 2.5×1015/cm-2/, the peakphotoresponse wavelength was tunable between 8.4μm to 10.2μm andPL peak from 780nm to 850nm.

The multi-well energy representation technique is developed for analyzing the valence band structures of strain-compensated multiple quantum well (SCQW) systems. Taking the energy eigenfunctions of both the heavy- and light-holes at the Γ point as the base vectors to set up the energy representation, we solve the Kohn-Luttinger Hamiltonian (KLM) equation in this representation, and obtain the quantized energy bands and the energy eigenvectors of both the heavy- and light-holes at the non- Γ points. By using this technique, the effects of the number of wells and the distance between wells on the valence band structures of SCQW systems can be analyzed efficiently, and the energy characteristic matrix obtained by this technique is much smaller than that of the k.p method, so the calculation can be performed more easily with a microcomputer.

Frequency of diode laser is stabilized by using saturated absorption spectroscopy, the linewidth of laser frequency is less than 1 MHz, and the offset of laser frequency can be controlled by using acousto-optical modulator. It satisfied the requirement of laser cooling and trapping of atoms, and thus has been used to the realization of laser cooling and trapping of rubidium atoms.

In this paper, a method for measuring thermally induced lossesin high-power end-pumped solid-state lasers has been proposed. Using this method, we haveinvestigated the variation of thermally induced losses with pump power, for two differentNd3+-doped YVOsub>4/sub>crystals (0.5%, and 2%), and with the ratio of mode radius to pump radius (Wsub>1/sub>/Wsub>p/sub>)taking on the value of about 0.5 and 1, respectively. The results show that thermallyinduced losses increase with the rising of the pump power, and strongly depend on Wsub>1/sub>/Wsub>p/sub>;large mode sizes lead to significantly high thermal losses. The results also reveal thatthe Nd3+concentration of Nd:YVOsub>4/sub>crystal has important influence onthermally induced losses;in the situation of large mode sizes, the thermal lossesassociated with heavily-doped crystals are much higher than those of lightly-dopedcrystals, and the dependence on Wsub>1/sub>/Wsub>p/sub>is much stronger.

In this paper, 370～nm laser is produced with its energy 8 J and pulsewidth 34～ns by using a Q-switched and frequency-doubled Cr:LiCAF laser system. Then, we use 370～nm laser as exciting light source to analyze the auto-fluorescence spectra of the solid samples of large intestine carcinoma and normal large intestine tissue, and gain the very valuable auto-fluorescence spectra for early detection of precancerous changes in colon tissue.

The structure and designprinciple of CO2 laser cosmetic instrument for removing wrinkle with a computercontrolling system is presented.The work principle of this device is introduced andanalyzed.

In this paper, thehardware of micro-computer controlling systems for “Vibrating mirror” driver and switch power supplyof CO2laser cosmetic instrument are presented, the automatic digital displaysystem and the softwares about the flow diagram of laser beam scanning are described.

Using binary statistic coding image processing method, the effect of decoy enclose target is simulated by computer in imparity average radiance. The result shows that in low radiance the target can not be detected by eyes, but through image processing the target can be detected. If the target need to be total hidden, decoy infrared radiance should be higher.

In this paper, the numerical simulation of master equation based on the DBTJ (Double Barrier Tunneling Junctions) of SET ( Single Election Transistor) using genetic algorithm are discussed. The numerical fittings are done for the Coulomb staircase of nanoscale particle self-assembly system. We find genetic algorithms are good for the fitting.

During the measurement of optical nonlinearities of sample in the thin film by Z-scan technique, ablating makes a hole in the thin film if the incidental laser power is too high, that will produce the error to measurement results. We analyze the positive and negative lens effect caused by the hole theoretically and give the expression of normalized transmittance in this condition.

To verify the correctness of a research result, more than two kinds of independent method are often needed to examine or calculate the same physics quantity. The carrier concentration in both n-type ZnSe:Cl and p-type ZnSe:N crystal films is evaluated with Hall and C-V technique, as well as far infrared spectrum technique. It is found that the experiment data obtained with these two kinds of way coincide well with each other. Therefore, we can confirm the ZnSe, a widegap semiconductor material for blue/green light emitting devices, of high doping level.

In this paper, the principle and automatic measurement system of angle-resolved scattering are described. The dynamic range, sensitivity and reproductively are discussed. The angle-resolved scattering distribution and polarization properties of polytetrafluoroethylene diffuse reflectance plate are measured under multiwavelength laser illumination in order to test the system function and properties.