Title :
Photoinduced Modifications in Fiber Gratings Inscribed Directly by Infrared Femtosecond Irradiation
Author :
Martinez, Amos ; Dubov, Michael ; Khrushchev, Igor ; Bennion, Ian
Author_Institution :
Photonics Res. Group, Aston Univ., Birmingham
Abstract :
The structure of fiber Bragg gratings inscribed point-by-point by an infrared femtosecond laser is studied by quantitative phase microscopy. Results show that these gratings present a central region with a depressed refractive index surrounded by an outer corona with increased refractive index. The refractive index profile suggests the presence of microvoids embedded in a region of the core
Keywords :
Bragg gratings; high-speed optical techniques; laser materials processing; optical fibre fabrication; optical microscopy; refractive index; fiber Bragg gratings; infrared femtosecond irradiation; microvoids; quantitative phase microscopy; refractive index; Bragg gratings; Coatings; Fiber gratings; Fiber lasers; Focusing; Laser beams; Microscopy; Phase measurement; Protection; Refractive index; Femtosecond microfabrication; fiber Bragg gratings (FBGs);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2006.884883
