On photo-expansion and microlens formation in (GeS2)0.74(Sb2S3)0.26 chalcogenide glass

► Photo-expansion induced by sub-band-gap photons in GeSbS glass. ► One-step microlens formation. ► The topography of the microlenses detected by AFM and DHM. ► The good mechanical characteristics of the microlenses were obtained. ► Local light-induced overheating of the glass.