Yan Min, Mortensen Niels Asger
Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark.
Opt Express. 2009 Aug 17;17(17):14851-64. doi: 10.1364/oe.17.014851.
Infrared (IR) light is considered important for short-range wireless communication, thermal sensing, spectroscopy, material processing, medical surgery, astronomy etc. However, IR light is in general much harder to transport than optical light or microwave radiation. Existing hollow-core IR waveguides usually use a layer of metallic coating on the inner wall of the waveguide. Such a metallic layer, though reflective, still absorbs guided light significantly due to its finite Ohmic loss, especially for transverse-magnetic (TM) light. In this paper, we show that metal-wire based metamaterials may serve as an efficient TM reflector, reducing propagation loss of the TM mode by two orders of magnitude. By further imposing a conventional metal cladding layer, which reflects specifically transverse-electric (TE) light, we can potentially obtain a low-loss hollow-core fiber. Simulations confirm that loss values for several low-order modes are comparable to the best results reported so far.
红外（IR）光对于短程无线通信、热传感、光谱学、材料加工、医学手术、天文学等领域而言至关重要。然而，一般来说，红外光比可见光或微波辐射更难传输。现有的空心芯红外波导通常在波导内壁使用一层金属涂层。这样的金属层虽然具有反射性，但由于其有限的欧姆损耗，仍然会显著吸收导光，特别是对于横向磁（TM）光。在本文中，我们表明基于金属线的超材料可以用作高效的TM反射器，将TM模式的传播损耗降低两个数量级。通过进一步施加传统的金属包层，该包层专门反射横向电（TE）光，我们有可能获得低损耗的空心芯光纤。模拟结果证实，几种低阶模式的损耗值与迄今为止报道的最佳结果相当。
