The spectral peculiarities of normal and tumor human tissues of different localization after sensitization by sodium fluorescein has been studied with help of multifrequency YAG:Nd laser. Fluorescence spectra of normal human tissue and breast, stomach, intestine, skin cancer at 355, 440 nm laser excitation were registered. The pharmacokinetic behavior of sodium fluorescein in normal and different tumor tissues has been investigated. The optimal time for diagnosis (12 - 18 hours after drug injection) was determined. The intensification of tumor tissue autofluorescence decreasing after sensitization of organisms by tumor seeking dye was observed. The electron excitation energy transfer from NAD(P)H to endogen chromophores or dyes localized in tumor has been discussed as possible reason of the observed phenomenon.
The main regularities of induced change of light polarization in the field of powerful ultrashort pulses in the resonant gaseous medium are investigated. Frequency- tunable ultrashort pulses allows to observe the polarization plane rotation at large values of detuning, in the different schemes of single-photon and two-photon interaction. On the other hand, the high intensity of these pulses allows to investigate the nonresonant interaction in the crystalline and solid transparent media. Our experiments carried out permit to propose the polarization technique for forming the given parameters pulses or train of pulses. In the observing medium placed between crossed polarizers, at counter propagation, powerful pump and linearly polarized probe pulses interact, because of which the probe pulse polarization changes. The polarization rotation angle as a time function is determined by the intensity of ultrashort pulse, the parameters of medium and frequencies of interacting waves. At the definite choice of the experimental conditions, requiring a probe wave after a crossed polarizer we can obtain the pulse which duration is determined by the length of medium, where interaction occurs. Using a nonresonant transparent media we have the possibility of forming the pulses of given duration tunable in a wide spectral region.