Optimization of the diffraction efficiency in non–uniform gratings in sillenite crystals (Bi12SiO20 and Bi12TiO2) considering the variation of fringe period, optical activity and polarization angles in a strong non–linear regime
G. Gonzálezª, A. Zúñigaª and F. Magañab
ª Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, México, Edificio 9, Unidad profesional Adolfo López Mateos, México D.F., 07730, México.
b Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20–364, México D.F 0100, México, e–mail: fernando@fisica.unam.mx
Recibido el 2 de julio de 2008 ]]> Aceptado el 27 de enero de 2009
Abstract
We included the non–uniformity of the grating and of the magnitude and phase of light modulation throughout the sample thickness to optimize the diffraction efficiency. The variation of fringe period, optical activity, birefringence, absorption of light, and polarization angle were considered. We studied strong nonlinear conditions and two crystal orientations one is with the grating vector parallel to the face [001] and the other is with the grating vector perpendicular to the same face. We included applied fields there is a complex relationship among all these parameters, and the prediction of the conditions for the optimum value of the diffraction efficiency is complicated. We report the optimal sample thickness for different situations, considering two wavelengths for reading: green (532 nm) and red (632 nm).
Keywords: Photorefractive gratings; refractive index; beam coupling; energy exchange; non–linear optics.
Resumen
Incluimos la no uniformidad de la rejilla y de la magnitud y de la fase de la modulación de la luz a lo largo del espesor de la muestra, para optimizar la eficiencia de difracción, considerando la variación del período de la rejilla, condiciones fuertemente no lineales, actividad óptica, birrefringencia, absorción, ángulo de polarización, campos aplicados y dos orientaciones del cristal: el vector de la rejilla paralelo y perpendicular a la dirección [001]. Existe una relación compleja entre todos estos parámetros y la predicción de las condiciones óptimas para la eficiencia de difracción es complicada. Reportamos el espesor óptimo de la muestra en diferentes circunstancias, utilizando dos diferentes longitudes de onda para la lectura: verde (532 nm) y roja (632 nm).
Descriptores: Rejillas fotorrefractivas; índice de refracción; acoplamiento de haces; intercambio de energía; óptica no lineal.
]]> PACS: 42.65.–k; 42.70.–a; 42.70.Nq.
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Acknowledgements
We wish to acknowledge partial financial support from Direccion General de Asuntos del Personal Académico from the Universidad Nacional de México through grant IN–111807.
References
1. P. Gunter and J.P. Huignard, Photo Refractive Materials and their Applications, (Springer–Verlag, Berlin, 1988) vol. I ; [ Links ] P. Gunter and J.P. Huignard, Photo Refractive Materials and their Applications, (Springer–Verlag, Berlin, 1989) vol. II. [ Links ]
2. P. Buchhave, S. Lyuksyutov, M. Vasnetsov, and C. Heyde, J. Opt. Soc. Am. B 13 (1996) 2595. [ Links ]
3. S.F. Lyuksyutov, P. Buchhave, and M.V. Vasnetsov, Phys. Rev. Lett. 79 (1997) 67. [ Links ]
4. S. Mallick, M. Miteva, and L. Nikolova, J. Opt. Soc. Am. B 14 (1997) 1179. [ Links ]
5. S.L. Hou, R.B. Laurer, and R.E. Aldrich, J. Appl. Phys. 44 (1973) 2652. [ Links ]
6. I. Foldvari, L.E. Halliburton, and G. J. Edwards, Sol. Stat. Com. 77 (1991) 181. [ Links ]
7. L.F. Magaña, I. Casar, and J.G. Murillo, Opt. Mater. 30 (2008) 979. [ Links ]
8. I. Casar, J.G. Murillo, and L.F. Magaña, Physics Letters A 352 (2006) 416. [ Links ]
9. N.V. Kukhtarev, G.E. Dovgalenko and V.N. Starkov, Appl. Phys. A 33 (1984) 227. [ Links ]
10. N.V. Kukhtarev, T.V. Kuktareva, J. Jones, E. Ward and H.J. Caulfield, Opt. Comm. 104 (1993) 23. [ Links ]
11. A. Marrakchi, R.V. Johnson, and J.A.R. Tanguay, J. Opt. Soc. Am. B 3 (1986) 321. [ Links ]
12. V.V. Shepelevich, N.N. Egorov, and V. Shepelevich J. Opt. Soc. Am. B 11 (1994) 1394. [ Links ]
13. VV Shepelevich, S F. Nichiporko, A.E. Zagaorskiy, Yi Hu and A.A. Firsov, Ferrolectrics 266 (2002) 305. [ Links ]
14. B.I. Sturman, et al., Phys. Rev. E 60 (1999) 3332. [ Links ]
15. J.G. Murillo, L.F. Magaña, M. Carrascosa and F. Agulló–López, J. Opt. Soc. Am. B15 (1998) 2092. [ Links ]
16. J.G. Murillo, L.F. Magaña, M. Carrascosa and F. Agulló–López, J. Appl. Phys. 78 (1995) 5686. [ Links ]
17. C.L. Woods, C.L. Matson and M.M. Salour, Appl. Phys. A 40 (1986) 177. [ Links ]
18. J.P. Herriau, D. Rojas, and J.P. Huignard, Ferroelectrics 75 (1987) 271. [ Links ]
19. Y.F. Kargin, et al. J. Cryst. Growth 275 (2005) 779. [ Links ] ]]>