用于高速电光调制器的SiO2/Si衬底上电容加载射频电极的性能
Performance of Capacitively Loaded RF Electrodes on SiO2/Si Substrates for High-Speed Electro-Optic Modulators
- Nokia Bell Labs（诺基亚贝尔实验室）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文实验研究了高阻硅衬底上电容加载行波射频电极，实现了低衰减和宽范围微波折射率调控，为薄膜铌酸锂等电光调制器提供了可扩展的衬底平台。
AI中文摘要：
我们在高阻硅衬底上热生长的SiO2上制备了常规和电容加载的行波射频电极，并对其在高速电光调制器中的性能进行了实验研究。电容加载电极的射频衰减系数低至约0.23 dB/cm/√GHz，与在绝缘石英衬底上制备的电极所报道的值相当，同时保留了硅衬底，避免了衬底去除或底切工艺。通过改变SiO2埋氧层（BOX）厚度和电容加载几何结构，微波有效折射率可以在很宽的范围内进行工程调控，同时保持较低的射频传播损耗。这使得在从紫外到电信C波段的宽光谱范围内实现微波-光速匹配成为可能。这些结果表明，热氧化硅为薄膜铌酸锂和薄膜钽酸锂电光调制器中的低损耗行波电极提供了一种简单且可扩展的衬底平台，也适用于集成收发器和共封装光学系统中的高速射频互连。
英文摘要：
We experimentally investigate conventional and capacitively loaded traveling-wave RF electrodes fabricated on thermally grown SiO$_2$ on high-resistivity silicon substrates for high-speed electro-optic modulators. The capacitively loaded electrodes exhibit RF attenuation coefficients as low as approximately $0.23~\mathrm{dB/cm}/\sqrt{\mathrm{GHz}}$, comparable to values reported for electrodes fabricated on insulating quartz substrates, while retaining the silicon handle and avoiding substrate removal or undercut processing. By varying the SiO$_2$ buried-oxide (BOX) thickness and the capacitive-loading geometry, the microwave effective index can be engineered over a broad range while maintaining low RF propagation loss. This enables microwave-optical velocity matching over a wide range of optical wavelengths, from the ultraviolet to the telecom C-band. These results demonstrate that thermally oxidized silicon provides a simple and scalable substrate platform for low-loss traveling-wave electrodes in thin-film lithium niobate and thin-film lithium tantalate electro-optic modulators, as well as for high-speed RF interconnects in integrated transceivers and co-packaged optical systems.
