Photosensitivity of Infrared Glasses under Femtosecond Laser Direct Writing for mid-IR Applications

oleh: Pierre Delullier, Laurent Calvez, Guillaume Druart, Florence De La Barrière, Christophe Humbert, Bertrand Poumellec, Matthieu Lancry

Format: Article
Diterbitkan: MDPI AG 2022-09-01

Deskripsi

Chalcogenide glasses are increasingly being developed for photonic applications, particularly in the field of mid-infrared optical imaging. In this paper, we study the photosensitivity of one chalcogenide to direct femtosecond laser writing and its possible applications to micro-optics. Particular attention has been paid to the creation of phase changes and related refractive index variations. This chalcogenide glass was compared with two commercial heavy oxide glasses: Schott SF10 and Corning 9754. We observed different types of permanent modifications depending on the writing speed and the laser pulse energy. Index variations were measured at <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="sans-serif">Δ</mi><mi>n</mi><mo>></mo><mo>+</mo><mn>0.055</mn></mrow></semantics></math></inline-formula> in the chalcogenide glass while maintaining spectral transmission similar to the pristine materials before irradiation. This provides a good candidate to design optical components for infrared application and helps to unlock the potential of the femtosecond laser direct writing technique to implement at high writing speed and high index changes with low optical losses.