Alonso-Ramos C, Ortega-Moñux Alejandro, Molina-Fernández I, Cheben P, Zavargo-Peche L, Halir R
Departamento Ingeniería de Comunicaciones, ETSI Telecomunicación, Universidad de Málaga, 29071 Málaga, Spain.
Opt Express. 2010 Jul 5;18(14):15189-200. doi: 10.1364/OE.18.015189.
Grating couplers are an efficient means for fiber to chip coupling, as they require no facet preparation and enable wafer scale testing. While grating couplers are commonly used in silicon wire waveguides, their application to micrometric silicon-on-insulator rib waveguides is complicated due to the presence of high-order Bloch modes. We study the Bloch modes behavior and their excitation determined by access waveguide design. The latter is implemented to enable single Bloch mode excitation. The use of a design process based on modal analysis is proposed. A grating coupler is proposed in silicon-on-insulator with 1.5 microm thick silicon layer that achieves a coupling efficiency of 65.6% at 1.55 microm. The structure, including interconnection waveguides, access waveguide and grating can be fabricated using a single lithography step.
光栅耦合器是实现光纤与芯片耦合的一种有效方式，因为它们无需进行刻面制备，并且能够进行晶圆级测试。虽然光栅耦合器在硅线波导中普遍使用，但由于高阶布洛赫模式的存在，其在微米级绝缘体上硅肋波导中的应用变得复杂。我们研究了由接入波导设计所决定的布洛赫模式行为及其激发情况。实施后者是为了实现单布洛赫模式激发。提出了一种基于模态分析的设计流程。在具有1.5微米厚硅层的绝缘体上硅中提出了一种光栅耦合器，其在1.55微米波长处实现了65.6%的耦合效率。包括互连波导、接入波导和光栅在内的结构可以通过单一光刻步骤制造出来。
