Multifunctional single‐crystal tellurium core multimaterial fiber via thermal drawing and laser recrystallization

Abstract

In the field of multimaterial optical fibers, the demand for high-performance single-crystal core glass-clad multimaterial optical fibers is increasing. However, the applications of single-crystal fibers are restricted by the complex fabrication processes and the slow growth of single-crystal materials. Here, a two-step method is demonstrated to achieve single-crystal tellurium (Te) core fibers with high crystal quality over the length of the fiber. This method starts with the thermal drawing of a fiber preform into polycrystalline Te core multimaterial fibers (precursor fibers) that are long and mechanically stable. A 532-nm continuous laser is then employed to recrystallize the Te core in the precursor fiber into a single crystal state along the entire length of the fiber. Experimental studies of these single-crystal fibers demonstrate that the single-crystal Te core fibers possess high transmittance (>90% at 2-10 μm) and high thermoelectric performance (ZT values from 0.03 to 0.13 at 300 K temperature). They are superior to previous reports and our previous work. This method works for fabricating various single-crystal fibers and has important applications in the field of optical fibers, functional fibers, and their integrated devices.

High-Performance n-Type Bi2Te3 Thermoelectric Fibers with Oriented Crystal Nanosheets

“…In the limited fiber core space, the nanosheets recrystallize continuously along the (001) plane and the fiber axis. It should be illuminated in a similar microstructural orientation during a single-crystal crystallization process by directional Bridgman annealing [ 19 ] or laser annealing [ 20 ]. In addition, there is elemental diffusion on the core–clad interface, which might cause surface roughness and low-dimensional defects of the fiber core, as in our previous study [ 9 ].…”

Enhanced broadband NIR emission in glass–ceramic fibers containing Nd3+/Yb3+ co‐doped YCa4O(BO3)3 disordered nanocrystal

“…Compared to the precursor fibers, the attenuation coefficient of recrystallized fibers is reduced by 34%. As the main loss mechanism in these fibers is absorption caused by impurities or scattering at the interface between core and cladding 42 . The decrease of the loss may be attributed to that the fiber core is transformed from amorphous state into crystal with fewer defects and regular arrangement after heat treatment 41 .…”

Purification and single crystallization of glass‐cladding GaSb core fiber using 532 nm laser‐driven thermal gradients

“…Notably, an exceptionally strong (1 1 1) diffraction peak was observed in the five times recrystallized GaSb cores, whereas the (2 2 0), (2 0 0), and (3 1 1) diffraction peaks disappeared. 24,25 This indicates that the recrystallized GaSb core has been transformed into a single-crystal GaSb or polycrystalline GaSb particles with a preferred orientation along the (1 1 1) plane. 25 Figure 3B is the single-crystal XRD diagram of the recrystallized GaSb core.…”