Optimization of sensitivity in long period fiber gratings with overlay deposition

The deposition of an overlay of higher refractive index than the cladding in a Long Period Fiber Grating (LPFG) permits to improve the sensitivity to ambient refractive index changes in a great manner. When the overlay is thick enough, one of the cladding modes is guided by the overlay. This causes...

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Detalles Bibliográficos
Autores: Del Villar, Ignacio, Matías Maestro, Ignacio, Arregui San Martín, Francisco Javier, Lalanne, Philippe
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2005
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/31089
Acceso en línea:https://hdl.handle.net/2454/31089
Access Level:acceso abierto
Palabra clave:Long Period Fiber Grating (LPFG)
Cladding modes
Overlay deposition
Descripción
Sumario:The deposition of an overlay of higher refractive index than the cladding in a Long Period Fiber Grating (LPFG) permits to improve the sensitivity to ambient refractive index changes in a great manner. When the overlay is thick enough, one of the cladding modes is guided by the overlay. This causes important shifts in the effective index values of the cladding modes, and henceforward fast shifts of the resonance wavelength of the attenuations bands in the transmission spectrum. This could be applied for improving the sensitivity of LPFG sensors. The problem is analysed with a numerical method based on LP mode approximation and coupled mode theory, which agrees with so far published experimental results.