A novel type of mid-IR microresonator, the chalcogenide glass (ChG) microfiber knot resonator (MKR), is demonstrated, showing easy fabrication, fiber-compatible features, resonance tunability, and high robustness. ChG microfibers with typical diameters around 3 μm are taper-drawn from As2S3 glass fibers and assembled into MKRs in liquid without surface damage. The measured Q factor of a typical 824 μm diameter ChG MKR is about 2.84×104 at the wavelength of 4469.14 nm. The free spectral range (FSR) of the MKR can be tuned from 2.0 nm (28.4 GHz) to 9.6 nm (135.9 GHz) by tightening the knot structure in liquid. Benefitting from the high thermal expansion coefficient of As2S3 glass, the MKR exhibits a thermal tuning rate of 110 pm·°C−1 at the resonance peak. When embedded in polymethyl methacrylate (PMMA) film, a 551 μm diameter MKR retains a Q factor of 1.1×104. The ChG MKRs demonstrated here are highly promising for resonator-based optical technologies and applications in the mid-IR spectral range.

中文翻译：

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中红外硫属化物超细纤维结谐振器

展示了一种新型的中红外微谐振器，硫属化物玻璃 (ChG) 微纤维结谐振器 (MKR)，显示出易于制造、光纤兼容的特性、谐振可调谐性和高稳健性。典型直径约为 3 μm 的 ChG 微纤维由 As2S3 玻璃纤维逐渐拉制而成，并在液体中组装成 MKR，而没有表面损坏。典型的 824 μm 直径 ChG MKR 的测量 Q 因子在 4469.14 nm 波长下约为 2.84×104。通过收紧液体中的结结构，MKR 的自由光谱范围 (FSR) 可以在 2.0 nm (28.4 GHz) 到 9.6 nm (135.9 GHz) 之间进行调谐。受益于 As2S3 玻璃的高热膨胀系数，MKR 在共振峰处表现出 110 pm·°C-1 的热调谐率。当嵌入聚甲基丙烯酸甲酯 (PMMA) 薄膜中时，直径为 551 μm 的 MKR 保留了 1.1×104 的 Q 因子。这里展示的 ChG MKR 在中红外光谱范围内非常有希望用于基于谐振器的光学技术和应用。