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We studied the influence of external electric field on two-wave mixing feature in a Ce: KNSBN crystal using a non-simultaneous readout device on the best writing conditions (with best polarization of writing beam). The effective gain and diffraction efficiency of two-wave mixing increased as well as the response time decreased as positive electric field increased applied along the c-axis of the crystal. The behaviors of two-wave mixing features mentioned were also observed in a negative electric field range of 0∼2000V/cm, but the effective gain began to decrease while the negative electric field was increased upon 2000V/cm, the response time increased as well.

The plasma emission spectra generated during the deposition process of Si-based thin films by radio frequency (RF) magnetron sputtering using Cu and Al targets in an argon atmosphere were acquired by the plasma analysis system, which consists of a magnetron sputtering apparatus, an Omni-lambda300 series grating spectrometer, a CCD data acquisition system and an optical fiber transmission system. The variation in Cu and Al plasma emission spectra intensity depending on sputtering conditions, such as sputtering time, sputtering power, the target-to-substrate distance and deposition pressure, was studied by using the analysis lines Cu I 324. 754 nm, Cu I 327. 396 nm, Cu I 333. 784 nm, Cu I 353. 039 nm, Al I 394. 403 nm and Al I 396. 153 nm. Compared with the option of experimental parameters of thin films deposited by RF magnetron sputtering, it was shown that emission spectra analysis methods play a guiding role in optimizing the deposition conditions of thin films in RF magnetron sputtering.

In the present paper, the productions by applying laser-induced plasma spectral analysis technique in different research fields were summarized. Many examples of the application based on laser-induced breakdown spectroscopy (LIBS) and laser-induced plasma spectroscopy (LIPS) methods were introduced, including the substance composition and correlative characteristics of the solid samples (e.g. metal alloy, soil, concrete, mineral, fossil, medicine etc.), liquid samples (e.g. solution, pure water, liquid jets etc.), and gaseous samples (e.g. air, pure gas, vapor and aerosol etc.). Some other investigations and applications were also included. The factors, which influence the detection capability, were discussed. Laser wavelength, pulse energy, power density, environmental atmosphere, external electric field, carbon layer on sample surface, sample material characteristic, and so on all have effects on the precision and the limit of detection. Finally, a simple introduction of the improvements in experimental equipment and methods was also covered. The development of laser-induced plasma spectral analysis technique creates favorable conditions, such as convenience and shortcut, for many science and application researches. It plays an important role in the progress in science and technology.

In the present paper, the effects of the ethanol-water solution temperature (20, 40, and 60 degrees C) on the emission intensity of ICP source, plasma parameters (excitation temperature and electron density), physical properties (surface tension and viscosity) of sample solution, and nebulization (uptake rate, effective uptake rate and nebulization efficiency) were studied by using optical-to-electrical detection method. The experimental results showed that the velocity of the sample entering the plasma increased, so that the line intensity of the elements Zn, Fe, Mg, Si, and Sr in water increased obviously with increasing the content of ethanol and the rise of the corresponding solution temperature. And the excitation capacity in the plasma was strengthened with the rise of the ethanol-water solution temperature. The maximal spectrum intensity of the elements Zn, Fe, Mg, Si, and Sr at 60 degrees C was higher by 55.8%, 45.4%, 48.9%, 17.7%, and 21.6% than that at 20 degrees C, respectively. It's valuable for the detection of the trace element.

Laser micro-spectral analyzer, coupled with CCD spectrometer, was used to determine soil elements in argon atmosphere at reduced pressure in the authors' experiment. The accuracy and availability of this method were studied. With Al I 394.40 nm and Ca II 396.85 nm as spectral analysis lines, using "the three standard samples method", the contents of Al and Ca in soil were determined. The results show that the maximum of relative standard deviation (RSD) of quantitative analysis is 5.80%; the maximum of relative difference between the quantitative analysis result and the standard value is 7.65%, suggesting that the accuracy of determination of Al and Ca in soil meets the challenge of quantitative analysis.

Copper plasma was induced with a high energy neodymium glass laser(0-25J) beam ablating the Cu target in argon atmosphere. It was observed that the line intensity of the emission spectra increases when the ambient pressure(0.1-0.5 MPa) rises. In order to study the enhancement mechanism, with the model of local thermodynamic equilibrium, the electron temperature was measured in argon atmosphere. The experimental results showed that electron temperature increases as the pressure rises. In addition, spatially resolved electron temperature was measured in Ar atmosphere at 0.1, 0.3, 0.5 MPa.

In an attempt to inhance the emission intensity of ICP, a conventional concentric pneumatic nebulizer was used with increased pressure, and the aqueous aerosol was partially let out to modulate the flow velocity of sample solution into the flame of the ICP. In the present work, the emission spectra of elements Ca, Si, Sr and Zn in water samples were measured, and the results showed that corresponding emission intensities are the highest at 0.05 MPa under the conventional condition, and after increasing the nebulizer gas pressure to 0.07 MPa and letting out part of aqueous aerosol, the peak values grew by 38%, 79%, 45% and 70%, respectively. In addition, the stability of the plasma radiation was not affected by the higher nebulizer gas pressure.

In the present paper, the effect of lens-to-sample distance (LTSD) on the radiative properties from the plasma induced by a high-energy neodymium glass laser (approximately 25J) in the argon ambient gas at a pressure of 0.43 x 10(5) Pa was studied. The experimental results showed that when the focus point of the focusing lens (f = 130 mm) shifts above and below the sample surface, the radiation intensities of the plasma, the excitation temperature, and the mass of ablated material are all changed, and their maxia appear at a focusing location of the laser beam, which is about 0.4 mm under the sample surface for alloyed-steel samples. If soil samples are used as the targets, the emission intensities of the laser plasma and the mass of ablated material have the maxima at a focus position about 0.2 mm below the sample surface. To investigate the influence of LTSD on the shape of the laser plasma, the images of the plasma formed have been shot in argon and air for the alloyed-steel samples. From these results, it was found that the properties of the laser plasma depend strongly on the LTSD.

A method for the determination of Eu in Long-aferglow of the SrAl2O4:Eu2+, Dy3+ phospher samples by laser microemission spectral analysis was developed. And the accuracy of this method was studied. Analyses of Eu in Long-aferglow of the SrA1204: Eu2+, Dy3+ phospher samples, using the Eu (11) line at 412.973 nm, show that RSD of relative intensity of spectral lines is 4.3%, RSD of quantitative analysis is 7.4%, the average of quantitative analysis is 2.13%. Compared with the content before samples synthesized, it can be concluded that the content of Eu in the SrAl2O4:Eu2+, Dy3+ phospher samples synthesized by high temperature solid phase reaction has an obvious increase.

The effect of solution temperature (20, 40 and 60 degrees C) on the emission intensity of ICP has been studied. The results show that the spectrum intensity of the elements Ba, Cu and Zn increases obviously with increasing the solution temperature. In addition, at different solution temperatures, the rule of the variation of the intensity with both observation height and nebulizer gas pressure has been obtained, which indicates that the best observation location is lowered when increasing the temperature, but the best nebulizer gas pressure is augmented.

In this experiment, the effects of gas composition and pressure on the intensity and quality of the plasma induced by a high-energy neodymium glass laser were studied. The experimental results show that the spectral intensity of the plasma in the argon atmosphere is stronger than that in the air when the pressure is the same. For the steel alloy sample, the intensities of the emission spectrum reach the maximum values when the argon pressure is 0.8 x 10(5) Pa. The self-absorption phenomena of Al II 308.22 and Al II 309.27 nm lines strengthen with the increase of the pressure, and even serious self-reversal appears when the pressure is (0.8-0.9) x 10(5) Pa. The temperature of plasma also raises with the increase of the pressure. When the argon pressure is 0.93 x 10(5) Pa, t h e temperature is about 1500 K higher than that when the argon pressure is about 0.43 x 10(5) Pa.

In this paper, the quality improvement of Laser Microprobe Emission Spectral Analysis (LMESA) lines in argon atmosphere at reduced pressure was experimentally investigated. The experimental setup consists of a YGJ-II laser micro-spectral analyzer and a photo-electro detection system. The temporal behavior and the intensity distribution of Cu I 324.7 nm and Cu I 327.4 nm lines of the copper alloy standard samples were studied. The results show that LMESA spectrum strongly depends on the environment gas, its pressure and the auxiliary excitation parameters. When the diameter at the end of graphite auxiliary electrodes is 1.5 mm, the distance between the electrodes is 4 mm, the center of the electrodes is 3 mm above the sample surface, the voltage of the auxiliary excitation is 1,300 V and the argon pressure is 33.2 Kpa, the emission time of Cu I 324.7 nm and Cu I 327.4 nm is about 500 microseconds longer than that in the air. The emission intensity of Cu I 324.7 nm and Cu I 327.4 nm is about 4 times higher than that in the air at the same pressure and is about 2 times higher than that in the air at normal pressure. The full width at half maximum of the spectral lines is obviously narrowed.

In this research, we experimentally studied the spectral quality of the CUl324.7nm and Cul327.4nm lines of the copper alloy standard samples in argon atmosphere at reduced pressure by a laser microprobe emission spectral analysis (LMESA) system. Compared with the results obtained in air atmosphere with the pressure of 760Torr, the spectral quality of the lines obtained obvious improvement. As the distance between the two graphite electrodes is 4mm and the pressure is 250Torr, the intensity of the spectral lines is about 2-3 times of that in the air atmosphere and the Full-Width-at-Half-Maximum (FWHM) is nearly one third of that in the air atmosphere.