Fabrication of erbium-ytterbium distributed multi-wavelength fiber lasers by writing the superstructured fiber Bragg grating resonator in a single writing laser scan

Abstract

We present an alternative method to fabricate multi-wavelength distributed-feedback fiber lasers made of superstructured chirped fiber Bragg gratings in a single writing laser scan with a custom period-profiled phase mask and a tailored amplitude apodization profile produced by phase mask dithering. This method simplifies the fabrication process and increases the yield of samples having the right number of laser lines and a small frequency error with respect to a reference grid.

UV-induced modification of stress distribution in optical fibers and its contribution to Bragg grating birefringence

“…The core fiber position was manually optimized to be close to the maximum focus of the f=5cm lens; the beam was more loosely focused in the other direction. The phase-mask was a chirped phase-mask with a mean period of , a mask period chirp of 0.625 nm.cm -1 and multiple π phase shifts separated by 2.18 mm (spacing of 50 GHz in the grating spectral response) [22]. During UV-beam scanning of the fiber, we used a decreasing multiple-step speed profile to vary the exposure level and create phase-shifted gratings of different strengths.…”