The dynamic process of the thermal distortion of the silicon mirror has been studied theoretically and experimentally. The displacement of the suface of the silicon mirror is varying rapidly in the beginning of the distortion. When the power of the incident laser is 200 W and the absorptivity of the silicon mirror is 70%, after two seconds the deflection of the mirror introduced by thermal stresses reachs 0.76 μm already. It is not a megligible problem for the high power short wavelength laser.

A novel binary optical element (BOE) used to transform the astigmatic and divergent beam emitted from a laser diode array (LDA) into an astigmation free and quasi collimated beam which has a rectangular cross section is introduced. The theory of design, fabrication methods, testing and experimental results and application of this BOE are discussed.

In this paper, according to the two dimensional vector coupled wave diffraction theory, we analyze diffraction properties of crossed binary phase gratings, and find that when the grating parameters are chosen properly, the gratings can have nearly zero reflectivities, and the antireflection properties have nothing to do with the polarization states of the incident lights.

By the electron conformation theory, the influence of laser field on enzyme activity is studied. The results show that laser field is advantageous to activation of enzymes.

In this paper, a novel hybrid passive component with a wavelength division multiplexer and a polarization insensitive optical isolator for an erbium doped amplifier is reported. The optimum design for hybrid component parameters by considering the characters of the hybrid component is presented. The hybrid component has the following features: insertion loss of signal light is less than 1.5 dB, the isolation of signal light is more than 42 dB, the insertion loss of pump light is less than 0.6 dB, and the 9 m diameter compnent is 45 mm long. We apply this hybrid component to an practical EDFA using the single forward pumping structure and achieve the small signal gain of about 30 dB, the noise figure less than 5 dB, and the saturated output power more than 10 dBm.

Multitarget detection using a real time joint transform correlator with power spectrum subtraction is proposed. It has two joint images in the input plane. In the second joint image, the reference image is contrast reversal. The two joint power spectra are subtracted using a diffraction grating. The D.C. term and undesired terms are substantially suppressed by this technique. It can yield strong auto correlation peak intensity, sharp auto correlation peak width, big peak to noise ratio, and the high capability of anti-background noise. Thus it produces higher accuracy of detection. Computer simulation results and optical implementation for input scences of the gray-scale multitarget are given. The experimental results have verified the correctness of the system design and performance analysis.

An important optical method of generating fractal pattern is described. A series of primary pictures are made by optical Fourier transformation and convolution operation. If all pictures are characterized by similar Fourier spectra, which have different scales, the optical fractal pattern can be obtained in the output plane. Experiments show that the regular fractal pattern can be generated by this method.

Based on the fact that there are unnegligible stochastic effects in the compensation of gain for the loss in the soliton communication system, the influence is studied of stochastic gain on the soliton transmitting system. The results show that the stochastic gain leads to the arrival time jitters, the variation of which is proportional to the cube of the propagation distance, and reduces the capacity of the system. The influence can be suppressed well by filters.

In this paper, we proposed a new laser photochemical ternary reactive system for preparing the PbS thin film. The composition and property of the deposited film were investigated by different techniques (absorption spectroscopy, scanning electron microscopy, X ray photoelectron spectroscopy, etc.). We have demonstrated the possibility of depositing sulphide films by this method.

A simple function is derived which gives the maximum pump power for the single frequency operation of an intracavity frequency doubled laser in terms of the cavity geometry and material parameters. This function is used to analyze the single frequency operation of intracavity frequency doubled Nd:YVO 4 and Nd:YAG lasers in detail.

The development of new laser media promotes the laser properties, but it brings some new problems. It can not be denied that the new laser medium such as Nd:YVO 4 improve the laser efficiency, but as we study its thermal effect, we find the non axial symmetry for its anisotropic thermal conductivity. Basing on the early thermal effect study of the diode end pumped laser medium, we put forward a mechanism of the thermal effect of the laser diode pumped anisotropic medium for the first time, and study the influence of the anisotropic thermal effect on laser properties.

The basic mechanism of the HF excitation of a CO 2 laser is discussed. The structure, technical featmes and experimental results of the new HF excited TF CO 2 laser are reported. The output of the laser is 1.5 kW, and the output beam divergence is smaller than 2 mrad.

With the multielectronic states model for investigation of molecular behavior in superstrong laser fields,we simulate numerically the evolution procedure of a molecular wavepacket in the superstrong laser field. It results that for high frequency field the wavepacket evolves gradually, the molecule doesn′t fully dissociate until the end of the interaction. However,the molecular wavepacket tunnels quickly into the dissociative states. The wavepacket overflows the interaction region only in the first several periods of the laser pulse. In addition, we have also compared the dissociation probability and the momentum distribution of fragments in the high-frequency field with those in the low-frequency field.

By analysing the limitation of the second moment definition of divergence angle and redefining this angle which is related to the beam width, we pointed out that the quality factor M2 is essentially a measure of the beam collimation. Taking the nonlinear self focusing optics phenomenon as an example, we illustrated that this factor could be smaller than one if the possible nonlinear effects become important. The discrepancy between the inequality M2≥1 in linear optics and the uncertainty relation of quantum mechanics was also emphasized.

In this paper, we derived an analytical solution of the pulsed beam propagating in the second order dispersive medium. Then, the GVD (group velocity dispersion), pulse front and the space time coupling of the pulse are analyzed.

By solving the effective mass equations using the difference method, taking into account the strain effects and valence band mixing effect, we have compared the band structures, DOS′s of valence band and the optical matrix elements for different shaped wells. With the same well width, rectangular well has the strongest confinement on carriers, but parabolic and triangular wells have flatter DOS curves, which are more analogous to step like DOS. Thus laser diode and semiconductor laser amplifier with these two kinds of wells as active layers may have lower transparent current densities. The mixing between valence subbands has greatly changed the optical matrix element, so it will have influence on the gain characteristics of quantum wells.

In this paper, the influence of stochastic gain on the amplified spontanesous emission noise is studied, and the variance of soliton time jitter is got by using the adjoint operator method. It shows that the stochastic gain has remarkable effect on the soliton time jitter. Finally, the results are analysed and a physical explanation is given.

We calculate the 4p and 5s inner shell doubly excited Rydberg states of rubidium The spectral region is between 50 and 70 nm There is a little difference of the spectra with the different configurations Here, we report 4p6 5s 2S1/2→4p5 5s(3P2,1,,1P 1)ns,nd, the spectra of doubly excited Rydberg states from inner shell excitation and compare them with new experimental results[1].

The resonance Raman effect is produced in a liquid core optical fiber. The Raman spectra intensity can be increased by 10 9 times. The resonance Raman spectrum of β carotene in CS 2 has been obtained. The concentration is 9.6×10 -12 mol/L. The laser power is 60 mW. The optical fiber length is 2.23 m, the inside diameter of the hollowcore optical fiber is 200 μm. In experiment we have found that frequency deviation of Raman spectra shifts when the concentration of β carotene in CS 2 is lower.

The electrostrictive force induced by beam interference can drive the acoustic wave,and enhance the stabillty of stimulated Brillouin scattering (SBS) phase conjugation fidelity. For the reflecting cell configuration pumped with a 2ns steep leading edge laser pulse, taking a two stage Nd glass amplifier and a SBS cell as a whole,it is shown that the measured far field distribution and phase conjugation fidelity of the output laser beam are more stable for θ≌5 mrad than those for θ>30 mrad.