High refractive index chalcogenide glass for photonic crystal applications

Abstract

A high refractive index Te-enriched bulk chalcogenide glass Ge(20)As(20)Se(14)Te(46) (n approximately 3.3) has been patterned by ablation using four- and two-beam interference femto-second laser setups operating at 800 nm. The regular arrays of 0.8 mum diameter and more than 0.8 mum depth holes and/or grooves of typical size of 1x1 mm(2) have been written on the surface of the glass in a time-scale of 1 second with 50 femtosecond pulses. The high photosensitivity of this narrow-gap semiconductor glass to the femtosecond irradiation is ascribed to a free electron absorption typical of metals, which is caused by laser-induced heating of the glass.

Enhanced surface patterning of chalcogenide glass via imprinting process using a buffer layer

“…Introducing surface structures featuring smoothly rounded edges onto chalcogenide glass, viz., grey-scale lithography, is normally not an easy task to perform when typical dry-etching or laser irradiation process is used [16,17]. Compared with this, the smooth curvatures formed by the viscous flow that mainly dominates in the surface region of chalcogenide glass in contact with a relatively hard stamp would be considered as one of the advantages of the imprinting technique.…”

Enhanced complete photonic bandgap in a moderate refractive index contrast chalcogenide-air system with connected-annular-rods photonic crystals

“…Making use of the photonic band gap (PBG) property of chalcogenide photonic crystals (PCs), various powerful functional optical devices have been designed or fabricated [2,3,[6][7][8][9][10][11][12][13][14]. If the PBG is increased, the performance of these PC devices would be further improved.…”

“…However, currently both the theoretical design and fabrication of three-dimensional (3D) PCs are challenging. Therefore, much attention has been put into the twodimensional (2D) chalcogenide PC [2,3,[6][7][8][9][10][11][12][13][14]. In the 2D PC, the modes of light waves could be decomposed into transverseelectric (TE) and transverse-magnetic (TM) polarizations.…”

Effect of Sn Addition on Thermal and Optical Properties of Pb9Se71Ge20-x

“…The better optical and thermal properties of these materials make them of potential use in the technological applications such as in photonics and phase change memories because of higher values of refractive index and lower value of phonon energy of these glasses [5,6]. The present Investigation on phase change memories (PCM) shows the possibility of obtaining multistate behavior, enhanced ability to withstand thermal cycling, and use of lower voltages for achieving desired phase change response by using the bilayers of Ge-chalcogenide and Sn-chalcogenide [7].…”

“…These materials can be used in the photonic crystal applications due to their higher value of refractive index. Photonic crystals are the materials which are used in photonic applications, such as optical band gap devices and omnidirectional reflectors [6]. It is necessary to have the knowledge of thermal stability and glass-forming ability (GFA) of material to know its suitability for the particular technological application before crystallization takes place.…”