Experimental and numerical demonstration of the acousto-optic effect applied in long period grating by means of
flexural waves is presented. The interaction between acoustic and optical waves is modeled with help of the method of
assumed modes, which delivers the strain field inside the grating and the transfer matrix method, which, given the strain
field as input, calculate the resultant grating spectrum. The experimental and theoretical results are found to be in good
agreement. The main effect of the bends in the grating is the break of degeneracy of the circular cladding modes, leading
the attenuation band to be changed. Among all the applications of this methodology, it is important to mention the
possibility of use as a tunable filter, laser cavity gain controller, switching device and transducer in sensing systems.