[New methods and technologies expandable to the laser detection of biological and medical samples].

The multicolour three-photon resonant photoionization spectra and high-time-resolved laser spectrum of UI were measured with a setup composed of a Nd:YAG-laser (532 nm, operated at 10 Hz)-pumped pulsed tunable dye laser system, a time-of-flight mass spectrometer, including micro-channel plate components, ns-oscilloscope, boxcar integrator, and so on. Creative inventions of this paper are for the first time by laser-induced quantum population of the graphic method, the causes for single-colour and two-colour three-photon resonant photoionization spectra peak were given in the three-colour three-photon resonant photoionization experiment; The question how to avoid producing single-colour and two-colour three-photon resonant photoionization spectra peak was solved, That is, how to solve the problem to avoid "false peaks", so that multicolour three-photon resonant photoionization purity was raised remarkably; On this basis, not only in close proximity to energy level position with just a difference 0.642 cm, the isotopes A and B of uranium, which are difficult to distinguish, were well resolved, but the two excited state lifetime values were obtained respectively. This technology is not limited to uranium spectrum, but more importantly, it's versatile. The new methods and technologies of basic research can be expanded to samples of biological and medical research fields with laser detecting and analysis.

[Measurement of the single-color three-photon resonant ionization spectrum of atomic uranium under the "equivalent wavelength effect laser" interaction].

Using Nd:YAG laser (532 nm) pumped mixed-dye laser, we obtained the output of this dye laser enhanced at the wavelength interval equivalent to that given by the copper vapor laser pumped dye laser. This measure favored us with the measurement of single-color three-photon resonant ionization spectrum of atomic uranium in the range of 562-586 nm, which is otherwise not efficiently covered by Nd:YAG laser pumped dye laser with any single dye. Thus 140 UI energy levels were obtained and the peaks of interest 575.814 nm and 575.836 nm were well resolved and their relative intensity determined.