Search results for " ZEE"
showing 6 items of 6 documents
Etude des effets cohérents dans la vapeur de rubidium atomique sous irradiation laser bi-chromatique
2013
The effect of electromagnetically induced transparency is observed, using nanocelland microcell. The EIT-resonance with good parameters (high contrast and small FWHM) is obtained in thick cells. The EIT-resonance splitting in magnetic field is observed for the cases of D1-line of 85Rb and 85Rb. The theoretical model, explaining the EIT-resonance components frequency shift dependence on magnetic field strength is presented. The theoretical and experimental results are compared and good agreement is shown. Also the EIT-resonance behavior in hyperfine Paschen-Back regime is presented and explained. For the first time the N-type resonance in microcell is observed. Good parameters of theN-type r…
Study of optical and magneto processes in Rb atomic vapor layer of nanometric thickness
2012
Using a narrow-band resonant fluorescence spectra from a nano-cell with a thickness of L= [lambda]/2, and VSOP resonances formed at a thickness L =[lambda] ([lambda] is the wavelength of the resonant radiation), for the first time it was experimentally investigated the behaviour of the frequency and intensity (transition probabilities) of the atomic hyperfine structure transitions between the 85Rb, 87Rb, D1 and D2 lines Zeeman sublevels in external magnetic fields in range 5 - 7000G. The behaviour of tens of previously unstudied atomic transitions was analyzed and it is demonstrated that the intensities of these lines can both greatly increase, and decrease (tenfold). For the first time it …
Study of optical and magneto-optical processes in cesium, rubidium and potassium micro- and nano-metric thin atomic layers
2016
It has been investigated the D1 line transitions of 39K atoms in external magnetic fields using nanocells for the cases of sigma+ and pi polarizations of laser radiation. For the first time it is demonstrated the decoupling of electronic total angular momentum J and nuclear momentum I (complete hyperfine Paschen-Back regime) in external magnetic field. For 39K the decoupling takes place at B >> 165 G. In the case of linear polarization it is shown that for B > 400 G the transmission spectrum consists of 2 groups of transitions and each group contains of one so-called "Guiding transition" (GT). The GT indicates the asymptotic value of all transitions probabilities in the group and the freque…
Formation of narrow optical resonances in thin atomic vapor layers of Cs, Rb, K and applications.
2019
This thesis presents the study of coherent light interaction with a sub-wavelength atomic alkali vapor layer confined in a nano-cell and applications for the formation of narrow optical resonances.We develop a theoretical model describing the resonant interaction of the laser light with the thin alkali vapor layer in the presence of an external static magnetic field. We show that due to a transient regime of interaction, only slow atoms contribute to the signal and their transmission spectrum is essentially Doppler-free. The nature of the obtained spectra makes the transmission spectroscopy from a nano-cell a convenient technique to perform studies of closely-spaced atomic transitions and i…
Competencias del Estado sobre los espacios marinos y sobre el espacio aéreo
2020
Competencias sobre los espacios marinos bajo la jurisdicción del Estado ribereño y fuera de la jurisdicción del Estado ribereño
Eulerin summia
2014
Tämän tutkielman tarkoituksena on tarkastella menetelmiä joilla voidaan laskea niin kutsuttuja Eulerin summia. Eulerin summia ovat Riemannin zeeta-funktion arvoja parillisissa ja positiivisissa kokonaislukupisteissä. Vaikka kyseessä on ääretön joukko äärettömiä summia, niin Eulerin summien laskemiseksi on mahdollista johtaa eksplisiittinen kaava. Tämä kaava johdetaan tutkielmassa kahdella eri tavalla: Bernoullin lukuja ja toisaalta Fourier-analyysin tuloksia hyödyntäen. Lisäksi tutkielmassa tarkastellaan muutamia menetelmiä, joilla voidaan laskea yksittäisiä Eulerin summia. Huomionarvoinen maininta on, että vaikka mielivaltainen äärellinen Eulerin osasumma on rationaalinen, niin kaikki Eule…