Controlled Optical Contrast Caused by Reversible Laser-Induced Phase Transitions in GeTe and Ge2Sb2Te5 Thin Films in the Spectral Range from 500 to 20,000 nm

• Published in: Journal of Russian laser research Vol. 44; no. 6; pp. 700 - 706
• Main Authors: Burtsev, Anton A., Kiselev, Alexey V., Ionin, Vitaly V., Eliseev, Nikolay N., Fedyanina, Mariya E., Mikhalevsky, Vladimir A., Nevzorov, Alexey A., Novodvorsky, Oleg A., Lotin, Andrey A.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.11.2023; Springer Nature B.V
• Subjects: Antimony telluride; Germanium; Lasers; Microwaves; Optical Devices; Optical properties; Optics; Phase transitions; Photonics; Physics; Physics and Astronomy; RF and Optical Engineering; Spatial distribution; Thin films; Transmissivity; laser-induced phase transition; phase-change material; optical properties
• ISSN: 1071-2836; 1573-8760
• DOI: 10.1007/s10946-023-10180-4

In this paper, we present the results of an experimental study of the controlled contrast of optical properties of Germanium Telluride (GeTe) and Germanium Antimony Telluride (Ge 2 Sb 2 Te 5 or GST) 100 nm thin films, caused by laser-initiated reversible phase transitions from the amorphous-tocrystalline state, and vice versa. We demonstrate a high contrast in the transmissivity and reflectivity spectra in the wide wavelength range from 500 to 20,000 nm. We show that such a contrast of optical properties can be controlled in the set–reset mode, when samples of thin films are exposed to a nanosecond laser pulse at a wavelength of 532 nm, with a spatial distribution close to “top hat.” We confirm the laser-initiated changes in the thin film structures by X -ray diffraction analysis methods.