Long period fiber gratings (LPFGs) with different periods in the standard single mode fiber were fabricated, using laser direct writing method, by femtosecond laser pulses with pulse width of 200 fs and the repetition rate of 250 kHz at a center wavelength of 800 nm in air. Comparative with bare LPFG in temperature sensor, LPFG had been encapsulated using large coefficient of thermal expansion of epoxy polymer and Aluminum to enhance the temperature sensitivity. The results showed that the temperature sensitivity of encapsulated LPFG was 2 times than that of bare LPFG. In addition, we also researched the relationship between resonant wavelength and surrounding refractive index (SRI) when LPFG immersed in refractive index of solution of different index at 20 degree Celsius.

Date Published: 29 November 2011
PDF: 7 pages
Proc. SPIE 8307, Passive Components and Fiber-Based Devices VIII, 83071W (29 November 2011); doi: 10.1117/12.904386

Published in SPIE Proceedings Vol. 8307:
Passive Components and Fiber-Based Devices VIII
Bishnu P. Pal, Editor(s)