Point-by-point inscription of fiber Bragg gratings into birefringent optical fiber through protective acrylate coating by Ti:Sa femtosecond laser

• Published in: Nauchno-tekhnicheskiĭ vestnik informat͡s︡ionnykh tekhnologiĭ, mekhaniki i optiki Vol. 15; no. 3; pp. 373 - 377
• Main Authors: Arkhipov, S.V., Grehn, M., Varzhel, S.V., Strigalev, V.E., Griga, N., Eichler, H.J.
• Format: Journal Article
• Language: English
• Published: Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University) 01.05.2016
• Subjects: acrylate coating; anisotropic fiber; Bragg grating; femtosecond laser; point-by-point inscription
• ISSN: 2226-1494; 2500-0373
• DOI: 10.17586/2226-1494-2015-15-3-373-377

The paper deals withpoint-by-point inscriptionof fiber Bragg gratings by the 800 nm Ti:Sa femtosecond laser pulses into a unique birefringent fiber with elliptical stress cladding of home manufacture. The proposed inscriptionmethod has advantages over the conventional phase mask method. The possibility to create complex grating structures and relatively high transparency of acrylate coating to the Ti:Sa femtosecond laser radiation of 800 nm gives the possibility for inscriptionof phase shifting gratings, chirped grating and superstructures without stripping the fiber. Also, this method makes it possible to inscribethese diffractive structures with and without co-doping of GeO2 in the fiber core. Achieved reflectance was 10%. The microscopic image of the diffractive structure in the fiber core is presented. The grating of 1.07 µm is realized by pulling the fiber with constant speed while the laser pulses are applied with a repetition frequency of 1 kHz. The results are usable in the sphere of creation of different fiber optic sensitive elements based on Bragg gratings.