Two different mechanical tuning devices of fiber Bragg gratings

Abstract

This paper presents two different devices for tuning fiber Bragg gratings. The first one is called the beam bending technique while the other is based on purely axial compression. We demonstrate that with a proper choice of the embedding material, the composite beam bending method constitutes an effective and reliable approach for tuning fiber Braggs gratings. We present a long-term stable device with a dynamic range of 80 nm which exhibits insertion losses smaller than 0.28 dB and small variations of the full width at half maximum. In order to reduce the amount of insertion losses, we also demonstrate a new tuning device for fiber Bragg gratings with a wavelength tuning range in excess of 65 nm. A purely axial tuning technique using a highly deformable polymer molded in cylinder shape is used to embed a fiber Bragg grating and to achieve a wavelength tuning range from 1551.7 to 1485.5 nm without insertion losses.