AI 中文总结
本研究研发了基于薄膜铌酸锂的高性能量子脉冲门，解决了传统量子脉冲门波长偏振组合受限、转换效率低的问题，实现了远超现有水平的转换效率，为实用化量子脉冲门奠定了基础。
AI 中文摘要
本研究展示了一款基于薄膜铌酸锂的量子脉冲门（QPG）。QPG可对量子光的时间模式进行选择性操控与探测，是光子量子技术众多应用的基础。迄今为止，其广泛应用受限于两大问题：参与场的波长与偏振组合受限，以及归一化转换效率低。我们通过研发基于薄膜铌酸锂的QPG克服了这些限制，设计了一种波导结构，可提供高效0型和频所需的色散特性。我们通过相位匹配强度映射验证了设计，并通过测量时间模式选择性达到(96.8±1.7)%（与现有QPG相当），证明了高质量的QPG运行。得益于薄膜铌酸锂中的强光场限制，我们在样品前泵浦功率仅为20mW时，实现了(89.6±0.1)%的内部转换效率，这使得归一化转换效率的下限估计值为(1810±10)W⁻¹cm⁻²，比此前的QPG高出三个数量级。我们的研究确立了薄膜铌酸锂是高性能QPG的理想平台，是迈向光子量子技术实用QPG的重要一步。
英文摘要
In this work, we demonstrate a quantum pulse gate (QPG) in thin-film lithium niobate. QPGs enable the selective manipulation and detection of temporal modes of quantum light and form the basis of numerous applications in photonic quantum technologies. To date, their widespread adaption is held back by two main limitations: restricted wavelength and polarization combinations of the involved fields and low normalized conversion efficiencies. We overcome these limitations through developing a QPG in thin-film lithium niobate. We design a waveguide geometry that provides the required dispersion properties for a highly efficient type-0 sum-frequency generation.We verify our design through mapping of the phase matching intensity, and demonstrate high-quality QPG operation by measuring a temporal-mode selectivity of (96.8$\pm$1.7)% on par with existing QPGs. Thanks to the strong confinement in thin-film lithium niobate, we succeed in demonstrating an internal conversion efficiency of (89.6$\pm$0.1)% for a pump power of only 20mW in front of our sample. This yields a lower-bound estimate for the normalized conversion efficiency of (1810$\pm$10)$\mathrm{W}^{-1}\mathrm{cm}^{-2}$, three orders of magnitude higher than in previous QPGs. Our results establish thin-film lithium niobate as ideal platform for high-performance QPGs and are a major step towards practical QPGs for photonic quantum technologies.
