High temperature sensing with fiber Bragg gratings in sapphire-derived all-glass optical fibers

• DOI: 10.1364/oe.22.026825
• Publication Date: 2014-10-21T19:43:09Z
• Authors: Tino Elsmann; Adrian Lorenz; Nazila Safari Yazd; Tobias Habisreuther; Jan Dellith; Anka Schwuchow; Jörg Bierlich; Kay Schuster; Manfred Rothhardt; Ladislav Kido; Hartmut Bartelt
• Keywords: 2. Zero hunger; 0103 physical sciences; 7. Clean energy; 01 natural sciences

A structured sapphire-derived all-glass optical fiber with an aluminum content in the core of up to 50 mol% was used for fiber Bragg grating inscription. The fiber provided a parabolic refractive index profile. Fiber Bragg gratings were inscribed by means of femtosecond-laser pulses with a wavelength of 400 nm in combination with a two-beam phase mask interferometer. Heating experiments demonstrated the stability of the gratings for temperatures up to 950°C for more than 24 h without degradation in reflectivity.