Control of the long period grating spectrum through low frequency flexural acoustic waves
; Possetti, G. R. C.
; Marques, C.
; Neves, P.T.
; Cook, K.
; Kamikawachi, R. C.
; Fabris, J. L.
; Canning, J.
; Pohl, A.
Measurement Science and Technology Vol. 22, Nº 4, pp. 045205 - 6pp, April, 2011.
ISSN (print): 0957-0233
ISSN (online): 1361-6501
Journal Impact Factor: 1,493 (in 2008)
Digital Object Identifier: 10.1088/0957-0233/22/4/045205
We have shown experimental results of the excitation of long period fiber gratings by means of flexural acoustic waves with a wavelength larger than the grating period, validated by numerical simulations. The effect of the acoustic wave on the grating is modeled with the method of assumed modes, which delivers the strain field inside the grating, then used as the input to the transfer matrix method, needed for calculating the grating spectrum. The experimental and numerical results are found to be in good agreement, even though only the strain-optic effects are taken into account.