CHIRPED FIBER BRAGG GRATING CAVITY RING-DOWN FOR STRAIN SENSING USING AN OTDR

• Autor(a) principal: Susana Oliveira Silva
• Data de Publicação: 2015
• Outros Autores: Passos,DJ, Manuel Joaquim Marques, Orlando Frazão
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://repositorio.inesctec.pt/handle/123456789/6551; http://dx.doi.org/10.1002/mop.29114

This work presents a fiber cavity ring down (CRD) configuration for the measurement of strain. An optical time-domain reflectometer (OTDR) was used to send impulses down into the fiber loop cavity, inside of which a chirped fiber Bragg grating was placed to act as a strain sensing element. This technique could provide strain results with both conventional CRD-based configuration and the OTDR. The CRD configuration provided a linear response to strain applied in the range 0-2000 epsilon, and a sensitivity of 1.34 ns/epsilon was obtained. For the same operation range, the OTDR interrogation allowed obtaining a periodic behavior due to fiber Bragg grating scanning of the wavelength peaks of the multimode laser source while increasing strain. It is shown that the OTDR interrogation method provide a ring-down time response of about 8 s which is a great improvement when compared to the conventional CRD configuration (23 s). (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1442-1444, 2015