University of Pardubice Faculty of Chemical Technology

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Photoinduced expansion and microlens formation on Ge-As-S glass surface

Authors: Samsonova Ekaterina | Kutálek Petr | Knotek Petr | Schwarz Jiří | Černošková Eva

Year: 2022

Type of publication: ostatní - přednáška nebo poster

Page from-to: nestránkováno

Titles:

Language	Name	Abstract	Keywords
eng	Photoinduced expansion and microlens formation on Ge-As-S glass surface	It is known that illumination of glasses surfaces causes many effects depending on the structure and composition of glass and on the wavelength/penetration depth of used illumination mainly. The oxide glasses generally have the high glass transition temperature, a wide bandgap (4-9 eV) and the structure is rigid [1]. So, the intense pulsed lasers or ultra-violet illumination are needed for inducing of these phenomena. On the other hand, the chalcogenide glasses have bandgaps lower than 4 eV and more flexible structures [2]. It is why the photoinduced effects can be created by using lower energy. We are focused here upon photoinduced volume changes on the surface of stoichiometric (GeS2)x (As2S3)(1-x) bulk glasses (x = 0, 27, 35, 59, 73, 82 and 95). These glasses were chosen because of their unique properties i.e., wide IR transparency, low phonon energy, good photosensitivity and optical nonlinearity. The glasses were prepared by a melt quenching method from pure elements (5N). The surface was polished to the optical quality (root means square ˂ 5nm). For the illumination was used CW laser (λ= 532 nm, the maximum laser power density up to 2000 W/cm2). The role of the chemical composition and exposition conditions (spot diameter ≈ 40, 60, 120 µm and time illumination 2, 5, 10 min) on microlens formation was investigated. The illumination led to the surface volume expansion and so to the microlenses formation. The highest microlenses ≈ 5,6 µm were obtained on the surface of glass with 59 mol % of GeS2. Created microlences were characterized by the Digital Holographic Microscope, Raman Spectroscopy, Atomic Force Microscopy, Energy-dispersive X-ray spectroscopy, Force Spectroscopy and obtained properties with non-illuminated surface were compared. From the dependence of the microlenses height on the illumination intensity the minimal energy of microlenses formation was also found.	Photoinduced; expansion; and; microlens; formation; Ge-As-S; glass; surface