A newly developed hyper-Rayleigh scattering (HRS) technique can be used forthe determination of the hyperpolarizability value of nonlinear molecules in solution or gas. The HRS signal can reflect both the intrinsic molecular properties and the intermolecular interactions. In this paper, the history, theory, research significance of the HRS technique and the current studies of the authors arepresented. The HRS experimental set-up and the analysis method are described and the advantages of the HRS over the classical EFISHG (electric field induced second-harmonic generation) technique are also summarized.

Phase shifting is the key technique in phase shifting interference metrology and it greatly effects the measuring precision even results in a failure. A high precision phase shifter is presented in this paper. The error of the output voltage is less than 0.1% and the error of the phase shifter is less than 3 degrees. The ESPI measuring system with the phase shifter described in this paper can reach a precision of λ/100.

Abstract This paper reports a new instrument for real-time monitoring 10～1500 W laser power and laser modes of stable performance and rapid response. The instrument may be useful in laser processing

Based on the technique of fiber-grating linear-tuning,this paper reports a new method of measuring fiber-grating transmission spectra using a pair of fiber-gratings of different spectral properties. This method is simple and effective. It is promising to become a new spectral technique. The experimental result is also presented.

This paper describes measurement of mirror reflectivity via cavity-ring-down-spectroscopy. The method can accurately determine the reflectivity of a mirror, using combination of linear and folded cavities. Results show that this method can measure reflectivity of mirrors of different sizes and media, at any reflection angles, possibly, under working circumstances.

This paper presents a theoretical study of the loss difference between the left and right elliptically polarized modes in differential laser gyro (DILAG), which is caused by the S-P phase and Q anisotropy of the cavity mirrors and the off-axial propagation of the laser in the quartz crystal. This loss difference could cause unexpected null-shifts of the DILAG and the study about it would be an important reference in improving the DILAG operation.

In this paper, the design principle of binary phase gratings with well-distributed diffraction intensities is discussed. Binary phase gratings with 16 orders well-distributed diffraction intensities are fabricated by using micro-electro technology and experimental results are given.

The general property of an assemble of a half-wave plate and polarizers is discussed by Jones algorithm. An expression for attenuation precision of the assemble is given. Finally, the experimental result of transmissivity property of an assemble, consisting of a 45 mm quartz half-wave plate and two polarizers, is reported.

The Monte Carlo method is a good way to calculate the received oceanic lidar signals, but its disadvantage is that the calculation efficiency is very low. The traditional semianalytic Monte Carlo method is improved in this paper, which includes a distorted Henyey-Greenstein function used to approximate the scattering phase function, and the expression of the scattering angle θ obtained from H-G function. The calculations from the received oceanic lidar signals are in good agreement with experiments.

A mathematical model describing frequency response characteristics of a stabilizer for laser intensity stabilization has been deduced. The relative experiments have also been carried out. The theoretic analysis is in agreement with the experimental results.

The 2-dimension imaging technique using scintillating fibres is described. The principle of the collection of the scintillation and the usage of the scintillating fibers in high energy physics is studied. At last, a simple scintillating fibers imaging system using scintillating fibers, enhancer, CCD camera, image capture card and computer is pretented.

The laser surface cladding technique was used to form a 30vol-% SiCp/Ni-Cr-B-Si-C composite coating on the AISI1045 steel substrate. The microstructure of the coating was investigated by SEM and TEM. SiCp had completely dissolved in the Ni based alloy during the laser processing. The bonding zone between the coating and the substrate had an eutectic structure, characterized by directional solidification and enrichment in Fe. The clad layer had a very fine microstructure which consisted of primary graphite G in the upper part of the Clad, closely spaced M23(C,B)6 dendrites in γ-Ni solid solution, and a small amount of lamellar eutectic Ni+Ni3(B,Si). TEM EDX compositional analysis showed a marked extension in solid solubility of Si in Ni solid solution because of the high cooling rate. M23(C,B)6 contains a high density of stacking faults. The microdiffraction pattern revealed a long periodicity of Ni3(B,Si).

Nanosize powder was formed by using excimer laser ablation of Si, Ti3+:Al2O3 and Cr3+:Al2O3 targets. The powders were analysized by transition electron micrography. The size ditribution was measured to get a closely log-normal relation with small geometric standard deviation.

AlN (Aluminum Nitride) thin films have been prepared with reaction between Al and nitrogen under the conditions of excimer laser irradiation of an aluminum target and nitrogen discharge the while. The effect of laser energy density, substrate temperature, and gas-discharging on the composition and construction of the films was discussed. The stoichiometrical preferred-orientation AlN (100) polycrystalline films were deposited on Si (100) wafers with DE=1.0 J*cm-2, PN2=13.333 kPa, Tsub=200℃, V=650 V, f=5 Hz, and dS-T=4 cm. The testing results show the band gap, the resistivity and the breakdown electric field of the films are 6.2 eV, 2×1013 Ω*cm and 3×106 V*cm-1 respectively.

Nanometer ceramic SiC powders have been synthesized by laser-induced Diethoxydimethylsilane. The process of the formation of the powders was studied. The powders produced were examined and characterized by various methods. At the same time, the crystallization behavior of the laser-synthesised nano amorphous SiC has been studied primarily. The results showed that the reaction temperature could be controlled by controlling the reactant flow rate, and the powders composition and structure could also be controlled. When the other conditions were fixed and the reactant vapor flow rates were 700～820 sccm, the ideal amorphous SiC nano-powders were produced. It was found that the initial crystallization temperature of the amorphous nano SiC powders was 1160℃and β-SiC could be obtained from the solid reaction of amorphous SiC.

The passive mode-locking in a pulsed Nd:YAG laser with a plane-concave cavity by using Cr4+:YAG as the saturable absorber was achieved. The pulse train with a pulse duration of 190 ps and output energy of 22 mJ was obtained. This paper also analyzed the dynamical progress of Cr4+:YAG passive mode-locking and the action of Kerr lens self-focus of Nd:YAG in the progress.

Using a xenon flash lamp as the pump source, Cr4+: YAG as a passive Q-switch, we have realized the green laser output at 0.53 μm from a self-frequency-doubling NYAB crystal. The green laser output energy, pulse width and repetition rate under conditions of different cavity lengths and small-signal transmission of Cr4+:YAG were measured. Meanwhile, Cr4+:YAG Q-switched coupling wave rate equations for NYAB crystal were given and numerical solutions of the equations were in agreement with the experimental results.

Based on the “inversion” of the half confocal cavity and the curve of gain distribution in the discharge zone,the various laser output patterns can be acquired by adjusting an infra-red coupling mirror coated with high reflective film. The output pattern is uniform and symmetrical. The result of expriment is in accordance with theory.

X-ray sources at high repetition rate were obtained in the experiments of the ultra-short pulsed laser (<60 fs) interaction with different target elements. The wavelength range was from 1 to 15 nm. With the energy of the incident laser increasing, the intensities of X-rays emitted from different elements are enhanced. The element which has the highest emission of L band is different with that in the experiments of long-pulse lasers interaction with targets. A pinhole transmission grating and X-ray CCD were used as detectors in our experiments.

Characteristics of light diffraction and diffraction free beams are analyzed. The criterion to diffraction free beams is discussed. It is pointed out that light diffraction means a non eigen solution beam of the wave equation degenerating into an eigen solution beam during propagation.

Recent studies have shown that the effect of third-order dispersion plays a detrimental role on the soliton-effect pulse compression in dispersion-shifted fibers. In this paper, we propose and numerically show that the effect of third-order dispersion on the soliton-effect pulse compression can be significantly suppressed if third-order dispersion of the fiber is periodically alternated between the normal and anomalous regimes.