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Quantum cooperative aspect between photons in Raman and hyper-Raman emissions


Author: Ţurcan Marina
Degree:doctor of physics and mathematics
Speciality: 01.04.02 - Theoretical and mathematical physics
Year:2016
Scientific adviser: Nicolae Enache
doctor habilitat, professor, Institute of Applied Physics of the ASM
Scientific consultant: VASEASHTA Ashok
doctor, profesor cercetător, Norwich University Applied Research Institutes, SUA
Institution: Institute of Applied Physics of the ASM

Status

The thesis was presented on the 5 January, 2016
Approved by NCAA on the 25 February, 2016

Abstract

Adobe PDF document0.87 Mb / in romanian

Thesis

CZU [535.14+530.145](043.2)

Adobe PDF document 3.28 Mb / in romanian
143 pages


Keywords

Raman laser, two-quantum transitions, Stokes and anti-Stokes photons, quantum effects.

Summary

The thesis consists of introduction, three chapters, general conclusions and recommendations, and bibliography of 125 references. This work contains 40 figures, is carried on 143 pages.

The results are published in 31 research papers.

Number of publications: Scientific result are published in 3 scientific journals, 9 conference proceedings and 19 conference abstacts.

Field of research: statistical physics, nonlinear optics and quantum optics.

The aim and objectives of the work: The aim of the work was to present the results of the researchers of quantum cooperative aspect between photons in the Raman and hyper-Raman emission, as well as the application of cooperative processes which appear at the nonlinear interactions of atomic subsystem and electromagnetic field of the cavity. Through the objectives of the thesis can be mentioned the quantum correlations between Stokes and anti-Stokes photon modes in the Raman and hyper-Raman emission. This correlation contains the grouping and coherent between photons Stokes and anti-Stokes modes in both emission of scattering processes.

Scientific novelty and originality of the results. For the first time was proposed quantified simultaneously pumping field and scattering field and forming bimodal coherent states in the cooperatively entanglement process. In the achievements so far only one of these fields was considered quantified while other classic.

The scientific problem solved in the field is that in fact the statistical properties of Stokes and anti-Stokes photon have been described by using the photons correlation functions. Coherence functions offer possibility to describe the quantum distribution function of photons generated in the scattering field as a function of photons conversion from Stokes to anti-Stokes mode. Since the lifetime of the atom in the cavity is considered smaller than cooperative scattering time between the Stokes and anti-Stokes fields, it was eliminated the atomic variables and was obtained the transformation of the Stokes bimodal field and anti-Stokes in coherent state.

The practical significance of the work. Is determined by the possibility of applying research results described in this thesis in elaboration of the devices transmitting information via photons collective. Quantum correlation between Stokes and anti-Stokes photon modes has been established by which it can be directed information. Quantum fluctuations relative of the intensity of photons from both modes tend to a minimum which demonstrates achievement of coherent states. These coherent states correspond to a minimum of the stabilization potential in RE and HRE, which is described by the existence of a critical point for the laser which begins to operate as a generator of stable intensity. The coherent fenomena between pair of the photons can be using both lithography and to work out two photons laser and maser.

Results implimentation: the results are used within the institutional project of fundamental scientific research 15.817.02.07F, strategic direction „Effects of optics and quantum kinetics in nanostructures for computing and advanced biophotonics”.