Optics of microlenses created by irradiation of As 2 S 3 amorphous chalcogenide films with femtosecond laser pulses.

Arrays of microlenses have been created on the surface of thin amorphous films of As2S3by localized photoexpansion induced by femtosecond laser pulses. The profile of a typical microlens has been mathematically described. Ray-tracing analysis has been performed to determine the focal points in the red and near-infrared spectrum of electromagnetic radiation. These lie at distances of 1.21 μm atλ = 650 nm and 1.33 μm atλ = 1.5 μm above the top of the microlens. It is suggested that the microlenses could be used in two-dimensional optoelectronic circuits or in fibre optics. [ABSTRACT FROM AUTHOR]