Tunable optical materials are indispensable elements in modern optoelectronics, especially in integrated photonics circuits where precise control over the effective refractive index is essential for diverse applications. Two-dimensional materials like transition metal dichalcogenides (TMDs) and graphene exhibit remarkable optical responses to external stimuli. However, achieving distinctive modulation across short-wave infrared (SWIR) regions while enabling precise phase control at low signal loss within a compact footprint remains an ongoing challenge. In this work, we unveil the robust electro-refractive response of multilayer ferroionic two-dimensional CuCrP₂S₆ (CCPS) in the near-infrared wavelength range. By integrating CCPS into silicon photonics (SiPh) microring resonators (MRR), we enhance light-matter interaction and measurement sensitivity to minute phase and absorption variations. Results show that electrically driven Cu ions can tune the effective refractive index on the order of 2.8 × 10⁻³ RIU (refractive index unit) while preserving extinction ratios and resonance linewidth. Notably, these devices exhibit low optical losses and excellent modulation efficiency of 0.25 V.cm with a consistent blue shift in the resonance wavelengths among all devices for either polarity of the applied voltage. These results outperform earlier findings on phase shifters based on TMDs. Furthermore, our study demonstrates distinct variations in electro-optic tuning sensitivity when comparing transverse electric (TE) and transverse magnetic (TM) modes, revealing a polarization-dependent response that paves the way for diverse applications in light manipulation. The combined optoelectronic and ionotronic capabilities of two-terminal CCPS devices present extensive opportunities across several domains. Their potential applications range from phased arrays and optical switching to their use in environmental sensing and metrology, optical imaging systems, and neuromorphic systems in light-sensitive artificial synapses.

可调谐光学材料是现代光电子学中不可或缺的元素，特别是在集成光子电路中，精确控制有效折射率对于各种应用至关重要。过渡金属二硫属化物 (TMD) 和石墨烯等二维材料对外部刺激表现出显着的光学响应。然而，在短波红外 (SWIR) 区域实现独特的调制，同时在紧凑的占地面积内以低信号损耗实现精确的相位控制仍然是一个持续的挑战。在这项工作中，我们揭示了多层铁离子二维 CuCrP ₂ S ₆ (CCPS) 在近红外波长范围内的强大电折射响应。通过将 CCPS 集成到硅光子 (SiPh) 微环谐振器 (MRR) 中，我们增强了光与物质的相互作用以及对微小相位和吸收变化的测量灵敏度。结果表明，电驱动的铜离子可以将有效折射率调整到2.8 × 10 ^-3 RIU（折射率单位）的数量级，同时保持消光比和共振线宽。值得注意的是，这些器件表现出低光损耗和 0.25 V.cm 的出色调制效率，并且对于所施加电压的任一极性，所有器件的谐振波长都具有一致的蓝移。这些结果优于基于 TMD 的移相器的早期发现。此外，我们的研究表明，在比较横向电（TE）和横向磁（TM）模式时，电光调谐灵敏度存在明显变化，揭示了偏振相关的响应，为光操纵的多种应用铺平了道路。两端 CCPS 器件的光电和离子电子功能相结合，在多个领域提供了广泛的机会。它们的潜在应用范围从相控阵和光学开关到环境传感和计量、光学成像系统以及光敏人工突触中的神经形态系统。