An exact solution of Lorentz force equation for an electron beam scattered by laser travelling wave is presented on the assumptions that the interaction between electrons and radiation of electrons are negligible. The relativistic classical scattering angular distributions are predicted which may be compared with experiments.
Our research shows that when the divergence of reiativistie electron beam entering into the wiggler increases, the gain of the free-electron lasers will be decreased and a small divergent angle will increase the output power. The maximum allowable divergent angle is determined by the laser oscillation conditions.
Ultrashort travelling wave amplified spontaneous. emission(A8B)is generated by transversal synchronizing pumping scheme with gradient distribution of pumping energy. 50 ps light pulses are generated by nitrogen laser pumping and 8 to 15 ps pulses generated by frequency doubled and mode-looked Nd:YAG laser pumping. The pulse shape and spectrum of the travelling wave ASE as well as the non-travelling wave ASE are measured by means of streak camera and optical multichannel analyzer. The computer simulation on the temporal behaviour of the travelling wave ASE is pressented and the calculation is in good agreement with the experimental results.
The superposed lines of 611.6178 nm and 611.6179 nm from highly-excited states f2D2 and f1D2 of nickel atoms have been resolved indirectty by means of laser-excited fluorescence spectrometry using a hollow cathode lamp. The linewidths were measured to be 2.1 GHz and 2.6GHz respectively.
Modulating the CO2 opto-galvanic voltage, signals from CO2-Na-He laser plasma have been analysed. It is shown that the amplitude of the COa opto-galvanic voltage is related to a change of the population of the CO2(0001) level and to the thermal relaxation rates of CO2 levels. Dependence of opto-galvanic voltage on the gain, intensity, dynamic resistance and temperature measured can be expressed by a solution similar to that OGE of CO molecule.
With the activation of fundamental laser wave (A=1.06m) the biological monolayers of chlorophyll A and carotenoid molecules were adsorbed by the optical surface. The SHG and THG signals of chlorophyll A and the THG signal of carotenoid have been observed. Also discussed is that the adsorbed monolayer of carotenoid can only generate THG singnal but not SHG.
Using two different methods an analytical expression of output intensity of SHG for rotatory crystal has been deduced and the possibility of its phas3 matching is disousssd.
Phase object ia inserted into one of the two beams of the Mach-Zehnder interferometer. With the two beams interfering1, nonlinear holograms are obtained. Using the high degree diffracted waves twice, we have obtained lower noise phase difference amplification of over 100 times. The theoretical results coincides with the experimental ones.
By utilizing the black-white synthetic PN (positive-negative) photograph for detection of difference-information between two photographs, the difference-information which is always immersed in the strong do component after the processing will now be selected and appeared due to the psendo-colour enhancement. As we make y=+l for the copy from the negative photograph, a wider dynamic range of H-D curve is provided.
The separation of deuterium from hydrogen have been carried out by infrared multiphoton dissociation in trifluoroacetaldehyde with 9.6umP(26) line from a TEA CO2 laser. The separation coefficient was 200 and the deuterium content of final composition was 80% from photolysis of gaseous GFBCHO containing 2.4% of GF3CDO. Adding helium could increase separation effect but oxygen would induce a chain reaction and lose selectivity.
The microstructure and element distribution of cobalt based coating processing with laser on 20* steel surface were studied by means of scanning electron microscope and electron probe. The results show that the fine metallurgical junction has been achieved on the surface and the content of coating elements equal nearly to zero in the host.
The change of chemical composition, concentration, valence and image of thin films for He-Ne laser mirrors within the lifetime have been studied with surface analysis methods such as XPS, SEM, and AES, etc., The results show that the damage and contamination of thin films lead to the failure of the lasers.
The experimental results show that (1) light reflection occurs not only from the skin surface, but also from tissue layers below the the skin; (2) between 400-800 mn, the absorption peak of reflectance curve of tha human body is at the same wavelength as that of the transmittance curve of the blood; (3) between 400-800nm, the reflectance and transmittance curve of the skin or that of the skin plus subcutaneous tissues have essentially the same changing tendency.
An analysis is made of the possibility of using unstable resonators in reducing the divergence of radiation from a high-gain, short inversion lifetime metal vapor laser. Comparison is made of the output laser beam characteristics with plane-concave and those of telescopic resonators. It is shown that to obtain an output beam with low divergence in such a laser, unstable resonators must be used.
17 cases of maglignant tumors and 3 cases of inflammatory ulcers in ENT were diagnosed by HpD, a He-Cd laser or a Hg-lamp and spectroscopic analysis from September 1985 to June 1986. Tumors, ulcers and normal tissues have a fluorescent peak at 640nm, but their intensities are obviously different, thus providing a basis for diagnosis of malignant tumors.