Tuning Fiber Bragg Gratings by Deformable Slides

Fiber gratings are key photonic elements having broad applications. Development of tunable fiber grating devices can provide a tunable “all-fiber” platform with extended applications. In this paper, we describe a novel deformable slide tuning technique that can achieve a large tuning range and a reliable tuning process. Fiber Bragg gratings at wavelength band of 1550, 1060, and 2000 nm have been tested, and shown to achieve around 50-nm tuning range of the center wavelength. Long-term stability is evaluated at better than 0.08 nm for a 1550-nm fiber Bragg grating tuned at 30-nm position. The tuning mechanism can also be configured for tuning the refractive index perturbation profile of the fiber grating, demonstrating that a regular fiber Bragg grating can be tuned to a purely phase-sampled fiber Bragg grating. By employing tunable fiber Bragg gratings, tunable fiber lasers can be built in a very compact and robust “all-fiber” configuration without a free-space optical path in the laser cavity, which is experimentally demonstrated in Er, Yb, and Tm doped fiber lasers.