Sensitivity Improvement of a Humidity Sensor Based on Silica Nanospheres on a Long-Period Fiber Grating

Sensors

Diana Viegas²  Javier Goicoechea¹  José Luís Santos²  Francisco Moita Araújo³  Luís Alberto Ferreira³  Francisco J. Arregui¹ 

[1] Universidad Pública de Navarra, Campus Arrosadia, 31006 Pamplona, Spain; E-Mails:;Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal;INESC Porto, Rua Dr. Roberto Frias, 378, 4200-465 Porto, Portugal; E-Mails:

关键词: Humidity sensor;    long-period fiber grating;    nanospheres;    electrostatic self-assembly;   

DOI  :  10.3390/s90100519

来源: mdpi

【 摘 要 】

This work addresses a new configuration that improves the sensitivity of a humidity sensor based on a long-period fiber grating coated with a SiO₂-nanospheres film. An intermediate higher refractive index overlay, deposited through Electrostatic Self-Assembly, is placed between the fiber cladding and the humidity sensitive film in order to increase the total effective refractive index of the coating. With this intermediate design, a three-fold improvement in the sensitivity was obtained. Wavelength shifts up to 15 nm against 5 nm were achieved in a humidity range from 20% to 80%.

【 授权许可】

CC BY   
© 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.