A gap fiber Bragg grating (g-FBG) is fabricated by cutting a uniform FBG in the middle to introduce a small air gap between the two sections. Numerical and experimental investigations show that the g-FBG has the characteristics of both a phase shifted FBG and a Fizeau interferometer. The peak transmission wavelength of the g-FBG can be tuned by adjusting the air-gap longitudinally or transversely with respect to the fiber center-axis. With a g-FBG as tunable intra-cavity filter, a tunable fiber ring laser with a narrow line-width is demonstrated. The wavelength tuning range of the laser is 0.12 nm with a output power flatness better than 0.9 dB. The 3 dB spectral line-width is less than 12 pm and output power is 3.68 dBm.

Date Published: 17 October 2012
PDF: 4 pages
Proc. SPIE 8421, OFS2012 22nd International Conference on Optical Fiber Sensors, 84214J (17 October 2012); doi: 10.1117/12.974813

Published in SPIE Proceedings Vol. 8421:
OFS2012 22nd International Conference on Optical Fiber Sensors
Yanbiao Liao; Wei Jin; David D. Sampson; Ryozo Yamauchi; Youngjoo Chung; Kentaro Nakamura; Yunjiang Rao, Editor(s)