Abstract

An overlay of higher refractive index than the cladding is deposited on a long-period fiber grating (LPFG). This causes large attenuation-band shifts in the transmission spectrum, which permits the improvement of the sensitivity of the device to ambient and overlay refractive-index changes. To obtain maximum sensitivity for specific overlay and ambient refractive indexes, an optimum overlay thickness (OOT) must be selected. For complex overlay refractive indexes, there is an additional phenomenon of vanishing of the attenuation bands. This occurs for specific overlay-thickness values. The problem is analyzed with a numerical method based on linearly polarized (LP)-mode approximation and coupled-mode theory. Experimental results are contrasted with theoretical ones.

© 2005 IEEE

Optimization of sensitivity in Long Period Fiber Gratings with overlay deposition

Ignacio Del Villar, Ignacio R. Matías, Francisco J. Arregui, and Philippe Lalanne
Opt. Express 13(1) 56-69 (2005)

Enhancement of sensitivity in long-period fiber gratings with deposition of low-refractive-index materials

Ignacio Del Villar, Ignacio R. Matias, and Francisco J. Arregui
Opt. Lett. 30(18) 2363-2365 (2005)

Influence on cladding mode distribution of overlay deposition on long-period fiber gratings

Ignacio Del Villar, Ignacio R. Matias, and Francisco J. Arregui
J. Opt. Soc. Am. A 23(3) 651-658 (2006)

Deposition of overlays by electrostatic self-assembly in long-period fiber gratings

Ignacio Del Villar, Miguel Achaerandio, Ignacio R. Matías, and Francisco J. Arregui
Opt. Lett. 30(7) 720-722 (2005)

Mode transition in high refractive index coated long period gratings

A. Cusano, A. Iadicicco, P. Pilla, L. Contessa, S. Campopiano, A. Cutolo, and M. Giordano
Opt. Express 14(1) 19-34 (2006)