Tong Limin, Gattass Rafael R, Ashcom Jonathan B, He Sailing, Lou Jingyi, Shen Mengyan, Maxwell Iva, Mazur Eric
Department of Physics and Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature. 2003 Dec 18;426(6968):816-9. doi: 10.1038/nature02193.
Silica waveguides with diameters larger than the wavelength of transmitted light are widely used in optical communications, sensors and other applications. Minimizing the width of the waveguides is desirable for photonic device applications, but the fabrication of low-loss optical waveguides with subwavelength diameters remains challenging because of strict requirements on surface roughness and diameter uniformity. Here we report the fabrication of subwavelength-diameter silica 'wires' for use as low-loss optical waveguides within the visible to near-infrared spectral range. We use a two-step drawing process to fabricate long free-standing silica wires with diameters down to 50 nm that show surface smoothness at the atomic level together with uniformity of diameter. Light can be launched into these wires by optical evanescent coupling. The wires allow single-mode operation, and have an optical loss of less than 0.1 dB mm(-1). We believe that these wires provide promising building blocks for future microphotonic devices with subwavelength-width structures.
直径大于传输光波长的二氧化硅波导广泛应用于光通信、传感器及其他领域。对于光子器件应用而言，减小波导宽度是很有必要的，然而，由于对表面粗糙度和直径均匀性有严格要求，制造具有亚波长直径的低损耗光波导仍然具有挑战性。在此，我们报告了用于可见光至近红外光谱范围内低损耗光波导的亚波长直径二氧化硅“线”的制造方法。我们采用两步拉伸工艺制造出了直径低至50纳米的长自立式二氧化硅线，这些线在原子水平上显示出表面光滑且直径均匀。光可以通过光学倏逝耦合注入到这些线中。这些线可实现单模运行，光损耗小于0.1 dB·mm⁻¹。我们认为，这些线为未来具有亚波长宽度结构的微光电器件提供了很有前景的构建模块。
