The chalcogenide semiconductor antimony telluride exhibits a sub-unitary refractive index as low as 0.7 at mid- to near-UV wavelengths between 220 and 400 nm, with the spectral width of the sub-unitary band, minimum index and associated extinction coefficient being controllable functions of alloy composition. As such it can enable step-index hollow-core optical waveguiding at ultraviolet wavelengths and thereby, for example, spectroscopic and sensing applications wherein the confinement of light and a fluid analyte in the same core volume maximizes sensitivity, thereby limiting required interaction lengths to as little as a few wavelengths.

中文翻译：

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具有亚单位指数硫属化物包层的紫外空芯波导

硫族半导体碲化锑在 220 至 400 nm 的中紫外至近紫外波长处表现出低至 0.7 的亚酉折射率，亚酉带的光谱宽度、最小折射率和相关消光系数是可控函数合金成分。因此，它可以实现紫外波长下的阶跃折射率空芯光波导，从而实现光谱和传感应用，其中将光和流体分析物限制在相同的核心体积中最大限度地提高灵敏度，从而将所需的相互作用长度限制为少到几个波长。