We present a new type of phase-shifted FBGs based on an in-grating bubble fabricated by femtosecond laser ablation together with fusion splicing technique. A micro-channel vertically crossing the bubble is drilled by femtosecond laser to allow liquid to flow in or out. By filling different refractive index liquid into the bubble, the phase-shift peak is found to experience a linear red shift with the increase of refractive index. Such a PS-FBG could be used to develop a promising tunable optical filter and sensor.

Date Published: 2 June 2014
PDF: 4 pages
Proc. SPIE 9157, 23rd International Conference on Optical Fibre Sensors, 915778 (2 June 2014); doi: 10.1117/12.2059446

Published in SPIE Proceedings Vol. 9157:
23rd International Conference on Optical Fibre Sensors
José M. López-Higuera; Julian D. C. Jones; Manuel López-Amo; José Luis Santos, Editor(s)