近红外单光子探测器的超表面调控机理及光场聚焦效应研究

There is an urge demand on the low cost, low power consumption, and non-deep low temperature operation near infrared InGaAs/InP single photon detector due to the national strategy on quantum communication, laser imaging and infrared detection. However, it cannot turn to the actual application because of the limitation of dark current of the detector. The metasurface has the potential to subvert the traditional dark current depression methods due to its powerful manipulation of light. In this project, we will cast aside the traditional electric manipulation methods to depress the dark current, such as single electrode blocking, surface passivation. The light modulation is adopted to maintain the luminous flux. The amorphous silicon based metasurface is integrated on the detectors with electron beam deposition. The mechanism of achromatic metamolecule for 1.31μm and 1.55μm is demonstrated. The method of polarization conversion and high transmission is also investigated. The direction factor and the additional phase of interference hologram is utilized to realize different number, shape, position and energy distribution of the focusing. The goal is to realize the perfect overlay of the achromatic focusing and the detection active area, leading to the depression of dark current and improvement of signal-noise ratio. The implement of this proposal will bring new energy in the NIR single photon detector and has important scientific and practical significance.

激光成像、量子通信、红外侦查等国家战略对低成本、小功耗、非深低温工作的近红外InGaAs/InP单光子探测器提出了迫切需求，由于器件暗电流大的制约导致无法开展实际应用。超表面因其对光场强大的调控能力而具有颠覆传统单光子探测器暗电流抑制手段的潜力。本项目摒弃传统电调控的方法，如单极阻挡、表面钝化等，采用光场调控的方式，在不牺牲入射光通量的前提下，探索超表面集成到探测器件上的手段，阐明超表面结构单元对1.31μm和1.55μm电磁波的消色差相位调控机理，揭示超表面高效的极化偏转和高透过率机制，利用方向控制因子和干涉全息附加相位实现聚焦光斑的个数、形状、位置、能量分布等有效控制，取得聚焦光斑与缩小的光敏元位置的高效契合，从而达到双色聚焦的目的，实现器件暗电流的有效抑制，提升器件信噪比。该项目的实施将为近红外半导体单光子探测器的发展注入活力，具有重要的科学意义和实用价值。

围绕量子保密通信、激光雷达、红外跟踪侦查等国家战略前沿技术对红外单光子探测核心器件的迫切需求，申请人开展了基于超构表面对红外光场多维度的优异调控特性，结合单光子探测器件物理与超表面的光场调控耦合，以研究发展超材料增强的红外单光子探测器为目标，开展了红外超表面的光子多维度调控机理、光耦合机制与空间排布与高效聚焦方法、光场调控对探测器件电调控参数的影响等问题研究，掌握了超表面结构的工艺制备最优参数，搭建了红外微区测试光路进行光场聚焦与探测器件性能表征，获得了偏振操控的宽带消色差超透镜，研制了高性能的单光子探测器件。项目执行期间，研究团队有2人获得国家自然科学基金优秀青年项目支持，1人获得上海市启明星计划支持，1人入选中国科学院青年创新促进会优秀会员，协助培养了4名博士和1名博士后等。上述结果的取得对高性能单光子探测器件的发展提供了支持和帮助。