Thermal emission is a ubiquitous and fundamental process by which all objects at non-zero temperatures radiate electromagnetic energy. This process is often presented to be incoherent in both space and time, resulting in broadband, omnidirectional light emission toward the far field, with a spectral density related to the emitter temperature by Planck's law. Over the past two decades, there has been considerable progress in engineering the spectrum, directionality, polarization, and temporal response of thermally emitted light using nanostructured materials. This review summarizes the basic physics of thermal emission, lays out various nanophotonic approaches to engineer thermal-emission in the far field, and highlights several relevant applications, including energy harvesting, lighting, and radiative cooling.
We present an overview of the framework of macroscopic quantum electrodynamics from a quantum nanophotonics perspective. Particularly, we focus our attention on three aspects of the theory which are crucial for the description of quantum optical phenomena in nanophotonic structures. First, we review the light-matter interaction Hamiltonian itself, with special emphasis on its gauge independence and the minimal and multipolar coupling schemes. Second, we discuss the treatment of the external pumping of quantum-optical systems by classical electromagnetic fields. Third, we introduce an exact, co…
A quantum emitter placed in a nanophotonic structure can result in non-reciprocal phenomena like chiral light excitation. Here, we present a theoretical model to couple circularly polarized emitters described by the density matrix formalism to the electromagnetic fields within a finite-difference time-domain (FDTD) simulation. In particular, we discuss how to implement complex electric fields in the simulation to make use of the rotating wave approximation. By applying our model to a quantum emitter in a dielectric waveguide and an optical circulator, we show how the excitation of the quantum …
Coherent interactions between quantum emitters in tailored photonic structures is a fundamental building block for future quantum technologies, but remains challenging to observe in complex solid-state environments, where the role of decoherence must be considered. Here, we investigate the optical interaction between two quantum emitters mediated by one-dimensional waveguides in a realistic solid-state environment, focusing on the creation, population and detection of a sub-radiant state, in the presence of dephasing. We show that as dephasing increases, the signatures of sub-radiance quickly …
Integration of solid state quantum emitters into nanophotonic circuits is a critical step towards fully on-chip quantum photonic based technologies. Among potential materials platforms, quantum emitters in hexagonal boron nitride have emerged over the last years as viable candidate. While the fundamental physical properties have been intensively studied over the last years, only few works have focused on the emitter integration into photonic resonators. Yet, for a potential quantum photonic material platform, the integration with nanophotonic cavities is an important cornerstone, as it enables…
对E. M. 50多年前的Purcell效应无疑已被证明是量子光学和纳米光子学丰富领域中最重要的效应之一。虽然在过去的几十年里，在这一领域的研究一直集中在电偶极子发射，最近的进展，在纳米纤维和磁量子发射体，如稀土离子的研究，刺激了自发发射的磁性方面的调查。本文综述了近年来利用各种纳米光子学系统增强磁偶极子量子发射体自发发射的研究进展。我们提供了描述磁发射体的Purcell效应的一般理论，概述了允许增强磁偶极子自发发射的特定纳米光子学结构的实现，并对该领域的挑战进行了展望，这些挑战对未来的研究仍然是开放的。
We introduce and experimentally demonstrate a new class of electrically driven thermal emitter based on globally aligned carbon nanotube metamaterials patterned as nanoscale ribbons. The metamaterial ribbons exhibit electronic and photonic properties with extreme anisotropy, which enable low loss, wavelength-compressed hyperbolic photonic modes along one axis and high electrical resistivity and efficient Joule heating along the other axis. Devices batch-fabricated on a single chip emit linearly polarized thermal radiation with peak wavelengths dictated by their hyperbolic resonances, and their…
Engineering Nanophotonic Modes via the Radiation Continuum
Laboratoire de Physique et d’Étude des Matériaux, LPEM, UMR 8213, ESPCI Paris, Université PSL, CNRS, Sorbonne Université（材料物理与表征实验室）；DOTA, ONERA, Université Paris-Saclay（ONERA巴黎萨克雷大学）；Centre de Nanosciences et de Nanotechnologies, CNRS – Université Paris-Sud-Paris-Saclay（纳米科学和纳米技术研究中心）
Metasurfaces have achieved fruitful results in tailoring complexing light fields in free space. However, a systematic investigation on applying the concept of meta-optics to completely control waveguide modes is still elusive. Here we present a comprehensive catalog capable of selectively and exclusively excite almost arbitrary high-order waveguide modes of interest, leveraging silicon metasurface-patterned silicon nitride waveguides. By simultaneously engineering the phase-matched gradient of the metasurface and the vectorial spatial modal overlap between the nanoantenna near-field and target…
Single solid-state quantum emitters offer considerable potential for the implementation of sources of indistinguishable single-photons, which are central to many photonic quantum information systems. Nanophotonic geometry optimization with multiple performance metrics is imperative to convert a bare quantum emitter into a single-photon source that approaches the necessary levels of purity, indistinguishability, and brightness for quantum photonics. We present an inverse design methodology that simultaneously targets two important figures-of-merit for high-performance quantum light sources: the…
Solution processible colloidal quantum dots hold great promise for realizing single-photon sources embedded into scalable quantum technology platforms. However, the high-yield integration of large numbers of individually addressable colloidal quantum dots in a photonic circuit has remained an outstanding challenge. Here, we report on integrating individual colloidal core-shell quantum dots (CQDs) into a nanophotonic network that allows for excitation and efficient collection of single-photons via separate waveguide channels. An iterative electron beam lithography process provides a viable meth…
Optical antennas are a fundamental element in optical phased arrays (OPA) and free-space optical interconnects. An outstanding challenge in optical antenna design lies in achieving high radiation efficiency, ultra-compact footprint and broad radiation angle simultaneously, as required for dense 2D OPAs with a broad steering range. Here we demonstrate a fundamentally new concept of a nanophotonic antenna based on near-field phase-engineering. By introducing a specific near-field phase factor in the Fraunhofer transformation, the far-field beam is widened beyond the diffraction limit for a given…
Optically active color centers in nanodiamonds offer unique opportunities for generating and manipulating quantum states of light. These mechanically, chemically, and optically robust emitters can be produced in mass quantities, deterministically manipulated, and integrated with a variety of quantum device geometries and photonic material platforms. Nanodiamonds with deeply sub-wavelength sizes coupled to nanophotonic structures feature a giant enhancement of light-matter interaction, promising high bitrates in quantum photonic systems. We review the recent advances in controlled techniques fo…
Nanophotonic engineering of light-matter interaction at subwavelength scale allows thermal radiation that is fundamentally different from that of traditional thermal emitters and provides exciting opportunities for various thermal-photonic applications. We propose a new kind of integrated and electrically controlled thermal emitter that exploits layered metamaterials with lithography-free and dielectric/metallic nanolayers. We demonstrate both theoretically and experimentally that the proposed concept can create a strong photonic bandgap in the visible regime and allow small impedance mismatch…
This work theoretically explores a spectrally selective TPV cell based on an asymmetric Fabry-Perot resonance cavity structure with sub-100-nm GaSb layer. The simulated spectral property of the ultrathin nanophotonic cell structure exhibits a high absorption peak above the bandgap due to the interference effect with electromagnetic field enhanced inside the GaSb layer between top and bottom silver electrodes, while the sub-bandgap absorption is as low as a few percent because of high reflectivity of the metal. An absorption enhancement nearly 20 times at particular frequency above bandgap is a…
Excitons spread through diffusion and interact through exciton-exciton annihilation. Nanophotonics can counteract the resulting decrease in light emission. However, conventional enhancement treats emitters as immobile and noninteracting. Here, we go beyond the localized Purcell effect to exploit exciton dynamics. As interacting excitons diffuse through optical hotspots, the balance of excitonic and nanophotonic properties leads to either enhanced or suppressed photoluminescence. We identify the dominant enhancement mechanisms in the limits of high and low diffusion and annihilation to turn the…
Singapore University of Technology and Design (SUTD)（新加坡科技设计大学）；Quantum Innovation Centre (Q. InC), Agency for Science Technology and Research (A*STAR)（科学技术研究局量子创新中心）；Department of Materials Science and Engineering, National University of Singapore（新加坡国立大学材料科学与工程系）；Department of Electrical and Computer Engineering, National University of Singapore（新加坡国立大学电气与计算机工程系）；Singapore-HUJ Alliance for Research and Enterprise (SHARE), The Smart Grippers for Soft Robotics (SGSR) Programme, Campus for Research Excellence and Technological Enterprise (CREATE)（卓越研究与科技企业园新加坡-希伯来大学科研联盟智能软体机器人夹爪项目）；Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH)（浦项科技大学人工智能研究生院）；Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR)（科学技术研究局材料研究与工程研究所）；School of Electronic Science and Engineering, Southeast University（东南大学电子科学与工程学院）；Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH)（浦项科技大学机械工程系）；Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH)（浦项科技大学化学工程系）；Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH)（浦项科技大学电气工程系）；POSCO−POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics（浦项-浦项科技大学-RIST平面光学与超光子学交叉研究中心）；Research School of Physics, Australian National University（澳大利亚国立大学物理研究学院）
Controllable strong interactions between a nanocavity and a single emitter is important to manipulating optical emission in a nanophotonic systems but challenging to achieve. Here a three-dimensional DNA origami, named as DNA rack (DR) is proposed and demonstrated to deterministically and precisely assemble single emitters within ultra-small plasmonic nanocavities formed by closely coupled gold nanorods (AuNRs). The DR uniquely possesses a saddle shape with two tubular grooves that geometrically allows a snug fit and linearly align two AuNRs with a bending angle <10°. It also includes a spacer…
