布拉格频率转换器：时空周期性在选择性参量频率转换中的交汇
The Bragg Frequency Convertor: A Meeting Between Spatial and Temporal Periodicities For Selective Parametric Frequency Translation
AI总结：
提出一种时空周期光栅概念，通过选择性调制高折射率或低折射率层实现定向频率转换，并基于硅脊波导结构进行了理论分析与实验验证。
摘要：
本研究介绍了布拉格频率转换器，这是一种时空周期光栅概念，将传统布拉格光栅扩展到动态领域，用于纯参量频率转换。通过选择性时间调制四分之一波堆栈的高折射率或低折射率层，该结构实现了定向频率转换：高折射率调制产生高效下转换，而低折射率调制产生上转换。这种层选择性源于不对称的布洛赫模式分布和相关的相位匹配条件。提出并分析了一种基于硅脊波导的实际实现方案，该波导具有周期性侧壁波纹和高折射率段的选择性掺杂。开发了耦合模理论来解释该机制，并通过全波仿真进行了验证。还提出了一种使用光泵浦的实验装置用于实际实现。结果确立了时间布拉格光栅作为一种多功能、可重构的平台，用于无杂散频率转换，在光信号处理和集成光子学中具有应用前景。
英文摘要：
This study introduces the Bragg Frequency Converter, a spatiotemporal-periodic grating concept that extends conventional Bragg gratings into the dynamic domain for pure parametric frequency conversion. By selectively time-modulating either the high-index or low-index layers of a quarter-wave stack, the structure achieves directional frequency conversion: high-index modulation yields efficient down-conversion, while low-index modulation produces up-conversion. This layer selectivity stems from the asymmetric Bloch mode distribution and associated phase-matching conditions. One practical realization, based on a silicon rib waveguide with periodic sidewall corrugations and selective doping of the high-index segments, is presented and analyzed. A coupled-mode theory is developed to explain the mechanism and validated through full-wave simulations. An experimental setup using optical pumping is also proposed for practical implementation. The theoretical and numerical results establish temporal Bragg gratings as a versatile, reconfigurable platform for spurious-free frequency conversion with applications in optical signal processing and integrated photonics.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
