scholarly journals Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Luca Sortino ◽  
Panaiot G. Zotev ◽  
Catherine L. Phillips ◽  
Alistair J. Brash ◽  
Javier Cambiasso ◽  
...  
Keyword(s):  
Refractive Index ◽  
Quantum Efficiency ◽  
Gallium Phosphide ◽  
High Efficiency ◽  
Single Photon ◽  
High Refractive Index ◽  
Coherence Time ◽  
Saturation Pulse ◽  
Single Photon Emitters ◽  
Nano Antennas

AbstractSingle photon emitters in atomically-thin semiconductors can be deterministically positioned using strain induced by underlying nano-structures. Here, we couple monolayer WSe2 to high-refractive-index gallium phosphide dielectric nano-antennas providing both optical enhancement and monolayer deformation. For single photon emitters formed on such nano-antennas, we find very low (femto-Joule) saturation pulse energies and up to 104 times brighter photoluminescence than in WSe2 placed on low-refractive-index SiO2 pillars. We show that the key to these observations is the increase on average by a factor of 5 of the quantum efficiency of the emitters coupled to the nano-antennas. This further allows us to gain new insights into their photoluminescence dynamics, revealing the roles of the dark exciton reservoir and Auger processes. We also find that the coherence time of such emitters is limited by intrinsic dephasing processes. Our work establishes dielectric nano-antennas as a platform for high-efficiency quantum light generation in monolayer semiconductors.

Design of the Diffuse Reflector Cup with Microstructure and the Research on the Optical Performance

2013 ◽  
Vol 372 ◽  
pp. 41-44
Author(s):  
Shi Bao Li ◽  
Da Ming Wu ◽  
Xiu Ting Zheng ◽  
Ying Liu ◽  
Yan Liu
Keyword(s):  
Refractive Index ◽  
Injection Molding ◽  
High Efficiency ◽  
High Refractive Index ◽  
Early Research ◽  
Light Energy ◽  
Energy Utilization ◽  
Optical Performance ◽  
Diffuse Reflector

The reflective properties and illumination uniformity of the polymer can be improved effectively with microstructure on the surface and scattering particles with high refractive index inside. The paper is based on the early research of the author. The reflector cup is processed by injection molding using the polymer of high reflective properties, which can achieve high efficiency of the light energy utilization and the uniform emergent ray.

scholarly journals Exciton-dielectric mode coupling in MoS2 nanoflakes visualized by cathodoluminescence

Nanophotonics ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Dung Thi Vu ◽  
Nikolaos Matthaiakakis ◽  
Hikaru Saito ◽  
Takumi Sannomiya
Keyword(s):  
Light Emission ◽  
Single Photon ◽  
Transition Metal Dichalcogenides ◽  
High Refractive Index ◽  
Scanning Transmission Electron Microscope ◽  
Optical Responses ◽  
Single Photon Emitters ◽  
Scanning Transmission ◽  
Metal Dichalcogenides ◽  
Energy Conversion Devices

Abstract Two-dimensional (2D) transition metal dichalcogenides (TMDCs), possessing unique exciton luminescence properties, have attracted significant attention for use in optical and electrical devices. TMDCs are also high refractive index materials that can strongly confine the electromagnetic field in nanoscale dimensions when patterned into nanostructures, thus resulting in complex light emission that includes exciton and dielectric resonances. Here, we use cathodoluminescence (CL) to experimentally visualize the emission modes of single molybdenum disulfide (MoS2) nanoflakes and to investigate luminescence enhancement due to dielectric resonances in nanoscale dimensions, by using a scanning transmission electron microscope. Specifically, we identify dielectric modes whose resonant wavelength is sensitive to the shape and size of the nanoflake, and exciton emission peaks whose energies are insensitive to the geometry of the flakes. Using a four-dimensional CL method and boundary element method simulations, we further theoretically and experimentally visualize the emission polarization and angular emission patterns, revealing the coupling of the exciton and dielectric resonant modes. Such nanoscopic observation provides a detailed understanding of the optical responses of MoS2 including modal couplings of excitons and dielectric resonances which play a crucial role in the development of energy conversion devices, single-photon emitters, and nanophotonic circuits with enhanced light-matter interactions.

scholarly journals Enhanced light-matter interaction in an atomically thin semiconductor coupled with dielectric nano-antennas

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
L. Sortino ◽  
P. G. Zotev ◽  
S. Mignuzzi ◽  
J. Cambiasso ◽  
D. Schmidt ◽  
...  
Keyword(s):  
Gallium Phosphide ◽  
Transition Metal Dichalcogenides ◽  
Optical Excitation ◽  
High Refractive Index ◽  
Two Dimensional ◽  
Metal Dichalcogenides ◽  
Light Matter Interaction ◽  
Efficient Coupling ◽  
Photonic Cavities ◽  
Nano Antennas

Abstract Unique structural and optical properties of atomically thin two-dimensional semiconducting transition metal dichalcogenides enable in principle their efficient coupling to photonic cavities having the optical mode volume close to or below the diffraction limit. Recently, it has become possible to make all-dielectric nano-cavities with reduced mode volumes and negligible non-radiative losses. Here, we realise low-loss high-refractive-index dielectric gallium phosphide (GaP) nano-antennas with small mode volumes coupled to atomic mono- and bilayers of WSe$${}_{2}$$ 2 . We observe a photoluminescence enhancement exceeding 10$${}^{4}$$ 4 compared with WSe$${}_{2}$$ 2 placed on planar GaP, and trace its origin to a combination of enhancement of the spontaneous emission rate, favourable modification of the photoluminescence directionality and enhanced optical excitation efficiency. A further effect of the coupling is observed in the photoluminescence polarisation dependence and in the Raman scattering signal enhancement exceeding 10$${}^{3}$$ 3 . Our findings reveal dielectric nano-antennas as a promising platform for engineering light-matter coupling in two-dimensional semiconductors.

scholarly journals Direct measurement of quantum efficiency of single-photon emitters in hexagonal boron nitride

Optica ◽  
2019 ◽  
Vol 6 (8) ◽  
pp. 1084 ◽  
Author(s):  
Niko Nikolay ◽  
Noah Mendelson ◽  
Ersan Özelci ◽  
Bernd Sontheimer ◽  
Florian Böhm ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Quantum Efficiency ◽  
Direct Measurement ◽  
Single Photon ◽  
Hexagonal Boron Nitride ◽  
Single Photon Emitters

scholarly journals High-efficiency subwavelength diffractive element patterned in a high-refractive-index material for 633??nm

1998 ◽  
Vol 23 (7) ◽  
pp. 552 ◽  
Author(s):  
Simion Astilean ◽  
Philippe Lalanne ◽  
Pierre Chavel ◽  
Edmond Cambril ◽  
Huguette Launois
Keyword(s):  
Refractive Index ◽  
High Efficiency ◽  
High Refractive Index ◽  
Diffractive Element ◽  
Refractive Index Material

scholarly journals All-dielectric metasurfaces for polarization manipulation: principles and emerging applications

Nanophotonics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 3755-3780 ◽  
Author(s):  
Yueqiang Hu ◽  
Xudong Wang ◽  
Xuhao Luo ◽  
Xiangnian Ou ◽  
Ling Li ◽  
...  
Keyword(s):  
Refractive Index ◽  
High Efficiency ◽  
High Refractive Index ◽  
Data Encryption ◽  
Optical Systems ◽  
Ohmic Loss ◽  
Imaging Data ◽  
New Paradigm ◽  
High Efficient ◽  
Low Efficiency

AbstractMetasurfaces, composed of specifically designed subwavelength units in a two-dimensional plane, offer a new paradigm to design ultracompact optical elements that show great potentials for miniaturizing optical systems. In the past few decades, metasurfaces have drawn broad interests in multidisciplinary communities owing to their capability of manipulating various parameters of the light wave with plentiful functionalities. Among them, pixelated polarization manipulation in the subwavelength scale is a distinguished ability of metasurfaces compared to traditional optical components. However, the inherent ohmic loss of plasmonic-type metasurfaces severely hinders their broad applications due to the low efficiency. Therefore, metasurfaces composed of high-refractive-index all-dielectric antennas have been proposed to achieve high-efficiency devices. Moreover, anisotropic dielectric nanostructures have been shown to support large refractive index contrast between orthogonal polarizations of light and thus provide an ideal platform for polarization manipulation. Herein, we present a review of recent progress on all-dielectric metasurfaces for polarization manipulation, including principles and emerging applications. We believe that high efficient all-dielectric metasurfaces with the unprecedented capability of the polarization control can be widely applied in areas of polarization detection and imaging, data encryption, display, optical communication and quantum optics to realize ultracompact and miniaturized optical systems.

Accelerated Discovery of High-Refractive-Index Polyimides via First-Principles Molecular Modeling, Virtual High-Throughput Screening, and Data Mining

2019 ◽  
Author(s):  
Mohammad Atif Faiz Afzal ◽  
Mojtaba Haghighatlari ◽  
Sai Prasad Ganesh ◽  
Chong Cheng ◽  
Johannes Hachmann
Keyword(s):  
Data Mining ◽  
Refractive Index ◽  
High Throughput ◽  
First Principles ◽  
High Throughput Screening ◽  
Large Scale ◽  
Computational Study ◽  
High Refractive Index ◽  
Structural Features ◽  
Learning Program

<div>We present a high-throughput computational study to identify novel polyimides (PIs) with exceptional refractive index (RI) values for use as optic or optoelectronic materials. Our study utilizes an RI prediction protocol based on a combination of first-principles and data modeling developed in previous work, which we employ on a large-scale PI candidate library generated with the ChemLG code. We deploy the virtual screening software ChemHTPS to automate the assessment of this extensive pool of PI structures in order to determine the performance potential of each candidate. This rapid and efficient approach yields a number of highly promising leads compounds. Using the data mining and machine learning program package ChemML, we analyze the top candidates with respect to prevalent structural features and feature combinations that distinguish them from less promising ones. In particular, we explore the utility of various strategies that introduce highly polarizable moieties into the PI backbone to increase its RI yield. The derived insights provide a foundation for rational and targeted design that goes beyond traditional trial-and-error searches.</div>

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