Amplitude- and Phase-Resolved Nanospectral Imaging of Phonon Polaritons in Hexagonal Boron Nitride

Polaritons are quasiparticles originating from strong interactions between photons and elementary excitations that could enable high tunability, tight electromagnetic field confinement, and large density of photonic states, making it possible to achieve novel and otherwise inaccessible functionalities. For these reasons, polaritons spawn great interest in the fields of physics, materials science, and optics for both fundamental studies as well as potential applications (e.g., modulators, photodetectors, photoluminescence, etc.). In recent years, the explosive growth of research in graphene and other 2D van der Waals materials is witnessed because they provide a new platform that substantially complements conventional metals, dielectrics, and semiconductors to investigate different polariton modes. This review highlights the works published in recent years on the topic of polariton photonics based on structured metals, graphene, and transition‐metal dichalcogenides (TMDs). The exotic optical properties of the polaritons in metallic structures and 2D van der Waals materials offer bright prospects for the development of high‐performance photonic and optoelectronic devices.

Section: Discussionmentioning

confidence: 99%

Polariton Photonics Using Structured Metals and 2D Materials

Cai

Wang

et al. 2019

“…In this context, SINS linescans and hyperspectral maps of hBN crystals can provide a direct view of polaritons waves in a multifrequency domain. Figure a,b shows spatiospectral maps of SINS amplitude and phase, respectively, obtained by a spectral linescan across the edge of an hBN crystal lying on SiO 2 . Both maps reveal the intensity contrasting modulations of the type I and type II polaritons.…”

Section: Sins and The Polaritons In Hbn‐based Structuresmentioning

confidence: 99%

“…In this figure, the authors adopted the wavenumber

\overset{true¯}{ν}

, with

\overset{true¯}{ν} = 1 / λ_{0}

Section: Sins and The Polaritons In Hbn‐based Structuresmentioning

confidence: 99%

Probing Polaritons in 2D Materials with Synchrotron Infrared Nanospectroscopy

Barcelos

Bechtel

Matos

et al. 2019

Self Cite

Polaritons, which are quasiparticles composed of a photon coupled to an electric or magnetic dipole, are a major focus in nanophotonic research of van der Waals (vdW) crystals and their derived 2D materials. For the variety of existing vdW materials, polaritons can be active in a broad range of the electromagnetic spectrum (meVs to eVs) and exhibit momenta much higher than the corresponding free‐space radiation. Hence, the use of high momentum broadband sources or probes is imperative to excite those quasiparticles and measure the frequency‐momentum dispersion relations, which provide insights into polariton dynamics. Synchrotron infrared nanospectroscopy (SINS) is a technique that combines the nanoscale spatial resolution of scattering‐type scanning near‐field optical microscopy with ultrabroadband synchrotron infrared radiation, making it highly suitable to probe and characterize a variety of vdW polaritons. Here, the advances enabled by SINS on the study of key photonic attributes of far‐ and mid‐infrared plasmon‐ and phonon‐polaritons in vdW and 2D crystals are reviewed. In that context the SINS technique is comprehensively described and it is demonstrated how fundamental polaritonic properties are retrieved for a range of atomically thin systems including hBN, MoS2, graphene and 2D heterostructures.

“…With a broadband probe light source, such as synchrotron light, high temperature plasma light source, or laser driven plasma, such setup, so‐called nano‐FTIR, can measure IR spectra with a spatial resolution of ≈20 nm . The technique has produced flourish results in phase transition materials, polariton dispersion, catalytic chemistry, biology, and geoscience, among other fields …”

Section: Experimental Technique and Polariton Detectionmentioning

confidence: 99%

Nanoimaging and Nanospectroscopy of Polaritons with Time Resolved s‐SNOM

Yao

et al. 2019

The development of electronics and photonics is entering a new era of ultrahigh speed sensing, data processing, and telecommunication. The carrier frequencies of the next‐generation electronic devices inevitably extend beyond radio frequencies, marching toward the nominally photonics‐dominated territories, e.g., terahertz and beyond. As a result, electronic and photonic techniques naturally merge and seek common ground. At the forefront of this technical trend is the field of polaritonics, where polaritons are half‐light, half‐matter quasiparticles that carry the properties of both “bare” photons and “bare” dipole‐carrying excitations. The Janus‐faced nature of polaritons renders the unique capability of operando control using photoexcitation or applied electric field. Here, state‐of‐the‐art ultrafast polaritonic phenomena probed by scattering‐type scanning near‐field optical microscope (s‐SNOM) techniques is reviewed. The ultrafast dynamical control and loss‐reduction of the polariton propagation are discussed with special emphasis on the creation and probing of the tip or edge induced plasmon– and phonon–polaritons in low‐dimensional systems. The detailed technical aspects of s‐SNOM and its possible future development are also presented.