Shaping the spectral characteristics of fiber Bragg gratings written in optical fiber taper using a phase mask method

Abstract

Fabrication of fiber Bragg gratings using a phase mask method, despite the substantial advantages, has a significant drawback. In this technique, the phase mask period determines the Bragg wavelength, and thus limits the possibilities of shaping its spectral characteristics. The paper presents the possibility of modifying the transmission and reflection spectra of fiber Bragg gratings written in a thermally tapered optical fiber using complex UV irradiation through a uniform phase mask. Structures with two Bragg wavelengths and with a narrow transmission band in the spectral characteristics were achieved by modifying the amplitude of refractive index changes and effective index distribution along the fiber taper. © 2012 Photonics Society of Poland.