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1Diffraction efficiency of a transmission hologram
M.A. Amanova1*, V.N. Naunyka2
1-Institute of Telecommunications and informatics of Turkmenistan, Ashgabat, 744000 Turkmenistan 2- Mozyr State Pedagogical University named after I.P. Shamyakin, Mozyr, 247760 Republic of Belarus
* maral_amanova@mail.ru
Taking into account the piezoelectric effect the dependence diffraction efficiency of holograms formed in a photorefractive Bii2SiO20 crystal sample on the orientation angle, specific rotation and crystal thickness was studied.
Using a sample of a Bii2SiO20 crystal cut (110) with a fixed thickness d=8 mm, the possibility of theoretically studying the dependence diffraction efficiency n of holograms on the orientation angle 9 and the specific rotation p of the crystal is demonstrated. The appearance of two "humps" on the surface n(9,p) at p=0.405 rad/mm cannot be explained without simultaneously taking into account the piezoelectric effect and optical activity.
It is shown that when the sign of the optical activity of a crystal changes, a shift in the maxima of the diffraction efficiency relative to the orientation angle equal to zero can occur mirror symmetrical for a plate 8 mm thick, asymmetrical for a plate 3.45 mm thick.
The dependence n(p) is not hypothetical. The specific rotation of the polarization plane of different Bii2SiO20 crystal samples can indeed be different [1]. In particular, this is due to the fact that when doping crystals during the growth process, the addition of various dopants (Cu, Fe) can cause a significant change in the specific rotation of the crystal. Therefore, studying the simultaneous influence piezoelectric effect and specific rotation of the crystal may be useful and the results obtained will be used for the purpose of preliminary selection of parameters in the practical solution of the problem optimizing the output energy characteristics of holograms.
[1] V.V. Shepelevich, S.M. Shandarov, A.E. Mandel, Light diffraction by holographic gratings in optically active photorefractive
piezocrystals, Ferroelectrics. - 1990. - Vol. 110. - P. 235-249.
