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Influence of Thermal Annealing on Ultrafast Laser‐Induced Local Densification in Bulk Sulfur‐Based Chalcogenide Glasses
Author(s) -
Somayaji Madhura,
D'Amico Ciro,
Wu Yiming,
Troles Johann,
Stoian Razvan
Publication year - 2019
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201800568
Subject(s) - materials science , chalcogenide , laser , ultrashort pulse , annealing (glass) , chalcogenide glass , germanium , sulfide , optoelectronics , optics , composite material , metallurgy , silicon , physics
The response to focused ultrafast laser pulses, of three bulk sulfur‐based chalcogenide glasses, gallium lanthanum sulfide (GLS) and two germanium arsenic sulfide with different stoichiometry (Ge 20 As 20 S 60 and Ge 15 As 15 S 70 ), is studied as a function of a thermal treatment made by several annealing cycles under the glass transition temperature. It is demonstrated that the annealing procedure has a considerable influence on the ultrafast laser‐induced local densification process of the quenched glasses. Using post‐mortem phase contrast microscopy and single‐mode light guiding measurements on photo‐inscribed waveguides, the influence of the thermal history on the laser‐induced positive refractive index changes (local densification) is determined. In particular it is shown that, in the case of the Ge 20 As 20 S 60 glass, the threshold of ultrafast laser‐induced densification in terms of laser energetic dose is considerably lowered after the first annealing cycle. In the light of this result, the activation of a new relaxation channel during the thermal treatment and its influence on the laser‐induced densification process of Ge‐As‐S glasses is discussed. Potential of material thermal pre‐treatment for developing efficient photo‐inscription techniques in the domain of integrated photonics is also discussed.