Crystalline GaSb-core optical fibers with room-temperature photoluminescence

Abstract

Glass-clad, GaSb-core fibers were drawn and subsequently laser annealed. The asdrawn fibers were found to be polycrystalline, possess Sb inclusions, and have oxide contamination concentrations of less than 3 at%. Melting and resolidifying regions in the cores using 10.6 µm CO 2 laser radiation yielded single crystalline zones with enhanced photoluminescence (PL), including the first observation of strong room temperature PL from a crystalline core fiber. Annealed fibers show low values of tensile strain and a bandgap close to that of bulk GaSb.

Laser restructuring and photoluminescence of glass-clad GaSb/Si-core optical fibres

“…In addition to unary crystalline semiconductor cores, there is increasing interest in binary and ternary 11–14 systems, where spatial variations in composition and associated band-gap and refractive index may be induced by laser treatment 15–17 . Semiconductor cores with direct band gaps may yield a variety of new optoelectronic devices, such as efficient fibre-based photo-detectors and sources 18,19 .…”

“…Semiconductor cores with direct band gaps may yield a variety of new optoelectronic devices, such as efficient fibre-based photo-detectors and sources 18,19 . Photoluminescence (PL) has been demonstrated in both II–VI and III–V compound semiconductor core fibres; with the latter system emitting at room temperature 11,14 .…”

Effect of Thermal Annealing on Mid-Infrared Transmission in Semiconductor Alloy-Core Glass-Cladded Fibers

“…SI fiber has a 32 µm alloy-core with a similar composition to the drawn SI fiber and GRIN fiber has a core with five layers. The most outer layer that is 100 at% Si, has 32 µm diameter and the most inner layer that is 100 at% Ge, has 16 lower losses at 3-7 µm region than the GRIN fiber, the transmission losses of the GRIN structure are uniform through the 2-14.8 µm region and it is around 30 dB/m that is at the same range with the SI fiber. Moreover, the GRIN structure features the suppression of the absorption peak of glasses around 10 µm which can be a promising fiber structure for longer wavelength applications such as the optical transmission of CO 2 lasers that have emission at 9-11 µm region.…”

“…Also it can form graded-index fibers that have not been reported in the mid-IR spectrum yet. Several studies were aimed to develop semiconductor alloycore fibers with various elements and compositions [13][14][15][16][17]. Recently, Si and Ge were used to form alloy-core fibers, however, the structural inhomogeneity of the alloy-core fibers causes high transmission losses, requiring post-fiber drawing processes [14,15].…”

CO2 laser annealed SiGe core optical fibers with radial Ge concentration gradients

“…These fibers can be made by high pressure chemical vapor deposition within a glass cladding [6,7], or fabrication with the molten core method [8] which is scalable over long lengths and can be used for bulk production [9] of these materials. Silicon core fibers exhibit extraordinary nonlinear optical properties [10][11][12], and Ge core fibers and compound materials [13,14] are also under development [15][16][17][18][19].…”