Diffraction efficiency in quasi-degenerate coupling in photorefractive materials

The aim of this work is to present theoretical analysis of the diffraction efficiency in sillenite BTO crystal, for mobile transmission gratings, where the effects of coupling beams are significant . In case of the degenerate coupling in photorefractive materials, the efficiency depends of the crys...

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Autores principales: Villamizar Amado, Astrid Lorena, Lizarazo, Zandra, Arias Hernández, Néstor Alonso, Molina Prado, Martha Lucía, Tebaldi, Myrian Cristina
Formato: Articulo
Lenguaje:Inglés
Publicado: 2019
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/124389
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Sumario:The aim of this work is to present theoretical analysis of the diffraction efficiency in sillenite BTO crystal, for mobile transmission gratings, where the effects of coupling beams are significant . In case of the degenerate coupling in photorefractive materials, the efficiency depends of the crystal thickness, coupling coefficient and the input intensity ratio. In the non-degenerate coupling case, the diffraction efficiency also depends on the response time of the photorefractive medium. This response time is the function of concentration ratio, i.e., of the relation between acceptor numbers and donor numbers. The diffraction efficiency is obtained by using coupled wave equations in onBragg regime using Method Runge-Kutta of order 4 in Matlab. The analysis considers the nonuniformity of the gratings inside the crystal, the concentration ratio of the material and detuning frequency.