Del Villar, IgnacioMatías Maestro, IgnacioArregui San Martín, Francisco Javier2018-04-052018-04-052005I. Del Villar, I. R. Matias and F. J. Arregui, "Long-period fiber gratings with overlay of variable refractive index," in IEEE Photonics Technology Letters, vol. 17, no. 9, pp. 1893-1895, Sept. 2005. doi: 10.1109/LPT.2005.8532831041-1135 (Print)1941-0174 (Electronic)10.1109/LPT.2005.853283https://academica-e.unavarra.es/handle/2454/28217A theoretical analysis is presented of a long-period fiber grating (LPFG) with an overlay of variable refractive index. The highest sensitivity of the resonance wavelengths to variations in the refractive index of the overlay can be optimized. There are two key points for a good design: the selection of an overlay refractive index close to that of the cladding of the LPFG and the overlay thickness. The problem is analyzed with a numerical method based on coupled-mode theory.application/pdfeng© 2005 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Coupled-mode analysisGratingsOptical fiber sensorsThin filmsArtículo / ArtikuluaAcceso abierto / Sarbide irekiainfo:eu-repo/semantics/openAccess