Electrostrictive excitation of acoustic waves in an optical fiber and their influence on propagation of optical pulses were theoretically investigated for the first time at the General Physics Institute in early nineties [1, 2]. Although the initial goal of this research was just to explain the long-range soliton interaction [3], the main features of this phenomenon were understood. According to the suggested model, large radial gradients of light intensity in single-mode fibers lead to electrostrictive excitation of transverse acoustic vibrational eigenmodes of the fiber structure. This causes temporal perturbation of the fiber effective refractive index, which in its turn results in phase modulation and frequency chirp of the carrier radiation. It was clear that this phenomenon may have widespread implications in fiber optics and, first of all, in optical fiber communication. That is why in recent years theoretical and experimental investigations of the effect of electrostrictive-induced acoustic waves on information transmission were carried out in a number of laboratories [4 - 8]. In this paper we present, for the first time, the results of theoretical investigation of electrostrictive response of single-mode ring-index profile fibers with a large effective mode area. Interest in such fibers is connected with the prospects of using large effective mode area fibers in WDM systems. The peculiar cross-section geometry of such fibers and much larger radial gradients of light intensity lead to strong changes in the electrostrictive response function. As in Ref. 2 the acoustic vibrations can be described by the equation for the components of displacement vector U_(i) (r,t) [9]
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