Photoinduced vector deformations of semi‐freely fixed glassy As‐S(Se)

Abstract

The chalcogenide glass is known to exhibit a variety of vector photo‐deformations. The present work studies the deformation in glassy As‐S(Se) films and flakes, which are laid on viscous grease layers. Upon bandgap illumination of linearly polarized cw laser light, the film and flake exhibit anisotropic wrinkles and extensions, respectively, while the directions change with the composition. As2S(Se)3 samples deform in the direction orthogonal to the electric field of the light, but pure Se deforms in parallel to the electric field. And, in the As‐Se system, an orthogonal‐parallel directional change appears at the As content of ∼1 at.%. X‐ray diffraction and Raman‐scattering spectroscopy detect no anisotropic atomic changes. The orthogonal deformation has been ascribed to optical pressure, while the parallel in Se may be triggered by polariton‐plasmon waves. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Photoinduced macroscopic vector deformations in chalcogenide glasses

“…1) of light [9]. which is in marked contrast to that in As 2 S(Se) 3 [9,10]. We also see, as exemplified in a side view of the second photograph, that these sinusoidal corrugations are manifestations of wrinkling deformations, which suggests that the film elongates in the wavy direction.…”

“…In addition, we performed subsidiary experiments for flakes of a-Se and c-Se to those previously reported [9]. Upon illumination of un-polarized light, a-Se flakes appeared to isotropically shrink, which is similar to the behavior in a-As2S3 [11].…”

“…For all the other films we see corrugations, the wavy direction being parallel to the electric field (vertical in Fig. 1) of light [9]. which is in marked contrast to that in As 2 S(Se) 3 [9,10].…”

“…In addition, interrelations between some deformations are vague. For instance, the present authors have recently demonstrated that, in As 2 S(Se) 3 and Se films deposited upon silicone grease layers, the directions of photoinduced wrinkling are contrastive; orthogonal and parallel to the electric field of linearly-polarized bandgap light [9], while the reason remain highly speculative.…”

“…For investigation of temperature dependence, samples were stored in a vacuum cryostat, the temperature of which was controlled using a Peltier device. Surface deformations were inspected and photographed using a digital microscope (Keyence, VHX-100), as in previous experiments [9][10][11][12]. X-ray diffraction patterns were obtained using a rotating Cu anode (Rigaku, RU-300), a LiF monochromator (for the Kα line), a Laue camera, and high-sensitive photographic plates with exposure times of ~8 h.…”