通过拓扑优化的近零介电常数双波长纳米腔中的增强交叉相位调制实现中红外单光子探测
Mid-Infrared Single-Photon Detection via Enhanced Cross-Phase Modulation in Topology-Optimized Epsilon-Near-Zero Dual-Wavelength Nanocavities
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中文总结 AI 辅助
研究通过格林张量量化理论，在双波长纳米腔中实现中红外单光子探测的交叉相位调制过程，得到可实现的XPM频移公式，经有限元模拟验证可行性，为中红外单光子非线性器件工程设计建立基准。
中文摘要 AI 辅助
我们使用格林张量量化理论研究具有吸收损耗的开放共振纳米结构，以研究纳米级克尔型近零介电常数（ENZ）材料在双波长纳米腔内单光子水平的交叉相位调制（XPM）过程，该材料具有有效非线性极化率χ(3)(ω)。我们得到了混合纳米腔中可实现的XPM频移的一般解析公式，该纳米腔同时捕获1.5μm的经典探测（信号）光束和3μm波长的单光子泵浦。通过关注室温下的中红外光子探测，我们对具有ENZ增强克尔型非线性的高迁移率氧化镉（CdO）纳米区域在量子非破坏模态下的单光子探测基本极限进行了全面分析，该区域嵌入由自由形式拓扑优化反向设计的周围硅（Si）环境中。我们在准正常模式的严格框架内使用有限元模拟对理论结果进行了数值实现，展示了单光子XPM频移Δfs≈18.4 GHz，分数频移（即频率牵引）Δfs/fs≈9.23×10−5，并解决了在提出的混合Si-CdO双波长纳米腔中使用经典探测光束或压缩探测态进行探测的可行性，超越了自相位调制噪声、热折射噪声、散粒噪声和电子抖动效应的传统限制。这项工作为中红外单光子非线性器件（如非破坏量子探测器、传感器和全光门）在固态光子平台上的工程设计建立了一个强大的基准。
英文摘要
We use the Green's tensor quantization theory for open resonant nanostructures with absorption losses to study cross-phase modulation (XPM) at the single-photon level in nanoscale Kerr-type epsilon-near-zero (ENZ) materials with an effective nonlinear susceptibility integrated inside dual-wavelength nanocavities. We obtain analytical formulas for the XPM frequency shifts in hybrid nanocavities that simultaneously trap a classical probe beam at 1.5 $μ$m and single-photon pump at 3 $μ$m wavelengths. We present a comprehensive analysis of the fundamental limits for mid-infrared single-photon detection in the quantum nondemolition modality for nanostructured cadmium oxide (CdO) regions with ENZ-enhanced nonlinearity embedded in a silicon (Si) environment inversely designed by free-form topology optimization. We numerically implement our theoretical results using finite element simulations within the rigorous framework of quasi-normal modes, demonstrating a single-photon XPM frequency shift $Δf_s \approx 55.6 \text{ GHz}$ with fractional shift (i.e., frequency pulling) $Δf_s / f_s \approx 2.78 \times 10^{-4}$ and addressing the feasibility of detection in the hybrid Si-CdO dual-wavelength nanocavity, either with a classical probe beam or a squeezed probe state, including the contributions of traditional limitations from self-phase modulation noise, thermorefractive noise, shot noise, and free-carrier absorption effects. Finally, we present a comparative size scaling analysis of the XPM phase shift and phase noise contributions for dual-wavelength nanocavities based on CdO and indium tin oxide (ITO) nonlinear ENZ materials. This work establishes a robust benchmark for the engineering of mid-infrared single-photon nonlinear devices such as nondemolition quantum detectors, sensors, and all-optical gates on a solid state photonic platform.
