您选择的条件: Wei Cai
  • Active plasmon interference control on ultrafast time scales by free electrons

    分类: 光学 >> 量子光学 提交时间: 2023-02-19

    摘要: Interference between light waves is one of the widely known phenomena in physics, which is widely used in modern optics, ranging from precise detection at the nanoscale to gravitational-wave observation. Akin to light, both classical and quantum interferences between surface plasmon polaritons (SPPs) have been demonstrated. However, to actively control the SPP interference within subcycle in time (usually less than several femtoseconds in the visible range) is still missing, which hinders the ultimate manipulation of SPP interference on ultrafast time scale. In this paper, the interference between SPPs launched by a hole dimer, which was excited by a grazing incident free electron beam without direct contact, was manipulated through both propagation and initial phase difference control. Particularly, using cathodoluminescence spectroscopy, the appearance of higher-order interference orders was obtained through propagation phase control by increasing separation distances of the dimer. Meanwhile, the peak-valley-peak evolution at a certain wavelength through changing the accelerating voltages was observed, which originates from the initial phase difference control of hole launched SPPs. In particular, the time resolution of this kind of control is shown to be in the ultrafast attosecond (as) region. Our work suggests that fast electron beams can be an efficient tool to control polarition interference in subcycle temporal scale, which can be potentially used in ultrafast optical processing or sensing.

  • Photocurrent imaging of hybrid polaritons in graphene based heterostructures

    分类: 光学 >> 量子光学 提交时间: 2023-02-19

    摘要: Photocurrent is arising as a powerful tool for detecting in-plane collective excitations in hybrid polariton systems. In this paper, based on the intrinsic optoelectric response of graphene, photocurrent imaging of in-plane plasmons from each graphene layer is presented in a hybrid graphene-graphene heterostructure. In combination with near-field optical signals which detect plasmons above the sample, three dimensional detection of hybrid plasmons is demonstrated. Especially, only an electronic boundary is necessary for the electrical detection of hybrid plasmons, which acts as both the photocurrent junction and plasmon reflector. Our studies would promote electrical studies of polariton related physical phenomena and pave the way towards all-electrical nano-optical processing.

  • Infrared full-Stokes polarimetry by parametric up-conversion

    分类: 光学 >> 量子光学 提交时间: 2023-02-19

    摘要: Polarimetry aims to measure polarization information of an optical field, providing a new freedom to enhance performance of optical metrology. Furthermore, the polarimetry in infrared (IR) range holds a promise for a wide range of academic and industrial applications because the IR light relates to unique spectral signatures of various complex chemicals. However, a primary challenge in IR applications remains lacking efficient detectors. Motivated by such a constraint, we present in this paper a nonlinear up-conversion full-Stokes IR Retrieval Polarimetry (IRP) that is able to decipher the IR polarization using a well-commercial and high-performance visible light detector. Assisted by a nonlinear sum-frequency generation (SFG) process in a lithium niobate thin film, the polarization states of the IR light are encoded into the visible SF wave. Based on a Stokes-Mueller formalism developed here, the IR polarization is successfully retrieved from SF light with high precision, and polarization imaging over the targets with either uniform or non-uniform polarization distributions are demonstrated. Our results form a fresh perspective for the design of novel advanced up-conversion polarimeter for a wide range of IR metrological applications.

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  • 制作维护:中国科学院文献情报中心知识系统部
  • 邮箱: eprint@mail.las.ac.cn
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