Low frequency peculiarities of the photorefractive response in sillenites

• Published in: Optics communications 1995, Vol.113 (4), p.371-377
• Main Authors: McClelland, T.E., Webb, D.J., Sturman, B.I., Mann, M., Ringhofer, K.H.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Optical materials; Optics; Other nonlinear optical materials; photorefractive and semiconductor materials; Physics
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/0030-4018(94)00616-3

We investigate experimentally and theoretically the dependence of the amplitude of the spatial fundamental grating, created by a pair of coherent light beams while using the running grating technique [ M.P. Petrov, S.I. Stepanov and A.V. Khomenko, Photorefractive Crystals in Coherent Optical Systems, Springer Series in Optical Sciences (Springer, 1991); P. Refregier, L. Solymar, H. Rajbenbach and J.P. Huignard, J. Appl. Phys. 58 (1985) 45], as a function of detuning frequency and beam ratio β in photorefractive Bi 12SiO 20. It is shown that for β > 0.05, in addition to the main peak in the frequency dependence of the amplitude, there is an additional peak of lower frequency which, as a rule, dominates the main peak. The position of the main peak depends on β. The experimental results are in good agreement with the theoretical analysis and the general ideas about excitation and nonlinear interaction of weakly damped space-charge waves.