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Information × Registration Number 0211U000426, 0111U002104 , R & D reports Title Theoretical investigations of ultimate characteristics of atomic frequency standards based on coherent population trapping. popup.stage_title Head Yatsenko L.P., Registration Date 07-02-2011 Organization Institute of physics NASU popup.description2 Object of investigations: atoms in coherent light fields. Methods of investigations: theoretical methods for analyses of processes of resonant interactions light with matter. The theoretical investigation of the broadening of coherent population trapping (CPT) resonances due to finite dimension of the laser beam (diffusion and transit-time broadening) for bichromatic laser field is investigated. An analyses of the diffusion broadening of the line is carried out for the realistic conditions of spatial finiteness both the laser radiation and the atomic gas. It is shown that the profile of the transmission line for infinite cell can be presented by superposition of the Lorentz profiles with weighting factors defined by the shape of the laser beam. The theoretical approach for calculation of CPT resonances in the cell with the atom vapour irradiated by a polychromatic field with equidistant spectral components (radiation of a femtosecond laser or a frequency shifted feedback laser) is developed. A lot of atomic groups contribute to resonance due to polychromatic field that enlarges registered signal. The theory takes into account coherence preserving collisions of the active atoms with the atoms of the buffer gas. The case of small laser fields which is particular interested for frequency standards we show that the influence of the polychromatic field can be reduced to bichromatic one with light shift of the frequency transition and the additional coupling of the metastable states. The conclusions about optimal parameters of the laser radiation for the enlarging precision of the frequency standards based on coherent population trapping are formulated. Controllable factor that shifts the CPT resonance frequency is light shift. It can be minimized by proper choice of two parameters of the laser radiation, namely the detuning of the spectral component with maximal intensity from the atomic transition frequency and the frequency difference of the adjacent spectral components. Product Description popup.authors Романенко Віктор Іванович Романенко Олександр Вікторович Яценко Леонід Петрович popup.nrat_date 2020-04-02 Close