Recent progress of semiconductor optoelectronic fibers

Abstract

Semiconductor optoelectronic fiber technology has seen rapid development in recent years thanks to advancements in fabrication and post-processing techniques. Integrating the optical and electronic functionality of semiconductor materials into a fiber geometry has opened up many possibilities, such as in-fiber frequency generation, signal modulation, photodetection, and solar energy harvesting. This review provides an overview of the state-of-the-art in semiconductor optoelectronic fibers, including fabrication and post-processing methods, materials and their optical properties. The applications in nonlinear optics, optical-electrical conversion, lasers and multimaterial functional fibers will also be highlighted.

Semiconductor Multimaterial Optical Fibers for Biomedical Applications

“…(Reprinted with permission from ref. [ 93 ]. Copyright 2021 Hei Chit Leo Tsui et al): ( a ) thermal drawing and ( b ) HPCVD.…”

“…Postprocessing techniques can enhance the performance of semiconductor optical fibers by increasing the crystallinity of semiconductors inside or by reducing element contamination, such as oxide contamination from glass cladding. All postprocessing procedures, with the exception of techniques aimed at reducing element contamination, rely on either thermal annealing or melt-recrystallization to heat a sample [ 93 ]. Common techniques used to enhance the multifunctional performance of fibers include thermal annealing [ 58 ], RPP [ 59 ], the interfacial modifier method [ 60 ], and laser treatment [ 61 ].…”

“…Thermal annealing is a process for controlling the characteristics of materials via crystal formation. During the process, materials do not remelt or recrystallize but rather have controlled nucleation of crystals, during which flaws are removed, and grain sizes are increased [ 93 ]. Thermal annealing can control the orientations of crystals that are produced, which may be crucial for certain purposes, such as nonlinear optics.…”

“…Similar techniques have been employed to reduce the optical loss of germanium core fibers [ 110 ]. In contrast to conventional annealing techniques, the semiconductors of fiber are regionally heated to a molten state and then recrystallized under precise control as the fiber is scanned past the laser’s focal point [ 93 ]. Unlike tapering methods, which must equally heat the core and cladding materials, laser processing allows for selective heating of either the core or the cladding, depending on the selected wavelength.…”

Localised structuring of metal-semiconductor cores in silica clad fibres using laser-driven thermal gradients

“…Novel core fibres as a platform for electronic and optical applications are of growing interest, as evidenced by a number of recent review articles 1 – 7 , and structuring of mixed material microstructures is an ongoing interest for the solar 8 – 10 , electronics 11 – 14 and photonic 15 , 16 communities. There are two temperature ranges that are encompassed in the fibre research, one with polymer-clad multimaterials, and one with conventional semiconductors in glass.…”