Mode-profile dependence of the electrostrictive response in fibers

The transverse optical intensity profile in fibers affects the efficiency of acoustic mode excitation by the optical field and the subsequent response of the field to the excited acoustic modes. The magnitude of the electrostrictive nonlinear coefficient for a square-top intensity profile will exceed that of a Gaussian profile by a fact of 2. For current fiber designs the range of values for n(2str) at zero frequency is expected to vary from 0.43 to 0.71 X 10(-16) cm(2) W-1 based on mode profile alone. The relative contribution of electrostriction to the total nonlinear response (electrostrictive + Kerr) in fibers increases proportionately as the mode profile flattens. (C) 1999 Optical Society of America OCIS codes: 060.2270, 060.4370, 060.4510, 060.5530, 190.4370.