<title>Polarization control in two-pass anisotropic optical systems with a new Faraday mirror</title>

Graphene oxide 2D films for integrated waveguide and ring resonator polarizers

10.31219/osf.io/7ex94 ◽

2020 ◽

Author(s):

David Moss

Keyword(s):

Graphene Oxide ◽

Liquid Crystal ◽

Ring Resonator ◽

Liquid Crystal Display ◽

Ring Resonators ◽

Optical Systems ◽

Resonant Cavities ◽

Polarization Control ◽

Core Components ◽

Polarization Division Multiplexing

Polarization selective devices, such as polarizers and polarization selective resonant cavities (e.g., gratings and ring resonators), are core components for polarization control in optical systems and find wide applications in polarization-division-multiplexing, coherent optical detection, photography, liquid crystal display, and optical sensing. In this paper, we demonstrate integrated waveguide polarizers and polarization-selective micro-ring resonators (MRRs) incorporated with graphene oxide (GO).

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Topological nanophotonics for photoluminescence control

Nanophotonics ◽

10.1515/nanoph-2020-0374 ◽

2020 ◽

Vol 10 (1) ◽

pp. 435-441

Author(s):

Aditya Tripathi ◽

Sergey Kruk ◽

Yunfei Shang ◽

Jiajia Zhou ◽

Ivan Kravchenko ◽

...

Keyword(s):

Rare Earth ◽

Material Science ◽

Optical Systems ◽

Dielectric Resonators ◽

Optical Antennas ◽

Light Sources ◽

Edge States ◽

Polarization Control ◽

Polarized Emission ◽

Rare Earth Doped

AbstractObjectivesRare-earth-doped nanocrystals are emerging light sources that can produce tunable emissions in colours and lifetimes, which has been typically achieved in chemistry and material science. However, one important optical challenge – polarization of photoluminescence – remains largely out of control by chemistry methods. Control over photoluminescence polarization can be gained via coupling of emitters to resonant nanostructures such as optical antennas and metasurfaces. However, the resulting polarization is typically sensitive to position disorder of emitters, which is difficult to mitigate.MethodsRecently, new classes of disorder-immune optical systems have been explored within the framework of topological photonics. Here we explore disorder-robust topological arrays of Mie-resonant nanoparticles for polarization control of photoluminescence of nanocrystals.ResultsWe demonstrate polarized emission from rare-earth-doped nanocrystals governed by photonic topological edge states supported by zigzag arrays of dielectric resonators. We verify the topological origin of polarized photoluminescence by comparing emission from nanoparticles coupled to topologically trivial and nontrivial arrays of nanoresonators.ConclusionsWe expect that our results may open a new direction in the study of topology-enable emission properties of topological edge states in many photonic systems.

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Scattering Properties of PT-Symmetric Chiral Metamaterials

Photonics ◽

10.3390/photonics7020043 ◽

2020 ◽

Vol 7 (2) ◽

pp. 43

Author(s):

Ioannis Katsantonis ◽

Sotiris Droulias ◽

Costas M. Soukoulis ◽

Eleftherios N. Economou ◽

Maria Kafesaki

Keyword(s):

Pt Symmetry ◽

Optical Systems ◽

Symmetric System ◽

Angle Of Incidence ◽

Asymmetric Transmission ◽

Chiral Metamaterials ◽

Polarization Control ◽

Gain Loss ◽

Incident Waves ◽

At Will

The combination of gain and loss in optical systems that respect parity–time (PT)-symmetry has pointed recently to a variety of novel optical phenomena and possibilities. Many of them can be realized by combining the PT-symmetry concepts with metamaterials. Here we investigate the case of chiral metamaterials, showing that combination of chiral metamaterials with PT-symmetric gain–loss enables a very rich variety of phenomena and functionalities. Examining a simple one-dimensional chiral PT-symmetric system, we show that, with normally incident waves, the PT-symmetric and the chirality-related characteristics can be tuned independently and superimposed almost at will. On the other hand, under oblique incidence, chirality affects all the PT-related characteristics, leading also to novel and uncommon wave propagation features, such as asymmetric transmission and asymmetric optical activity and ellipticity. All these features are highly controllable both by chirality and by the angle of incidence, making PT-symmetric chiral metamaterials valuable in a large range of polarization-control-targeting applications.

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Atomic Resolution in Crystal Aperture Stem

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100179932 ◽

1990 ◽

Vol 48 (1) ◽

pp. 236-237

Author(s):

J T Fourie

Keyword(s):

Optical System ◽

Spherical Aberration ◽

Three Dimensional ◽

Transmission Function ◽

Optical Systems ◽

Bragg Angle ◽

Electron Optical System ◽

Intimate Contact ◽

Diffraction Effects ◽

Design Aspect

The attempts at improvement of electron optical systems to date, have largely been directed towards the design aspect of magnetic lenses and towards the establishment of ideal lens combinations. In the present work the emphasis has been placed on the utilization of a unique three-dimensional crystal objective aperture within a standard electron optical system with the aim to reduce the spherical aberration without introducing diffraction effects. A brief summary of this work together with a description of results obtained recently, will be given.The concept of utilizing a crystal as aperture in an electron optical system was introduced by Fourie who employed a {111} crystal foil as a collector aperture, by mounting the sample directly on top of the foil and in intimate contact with the foil. In the present work the sample was mounted on the bottom of the foil so that the crystal would function as an objective or probe forming aperture. The transmission function of such a crystal aperture depends on the thickness, t, and the orientation of the foil. The expression for calculating the transmission function was derived by Hashimoto, Howie and Whelan on the basis of the electron equivalent of the Borrmann anomalous absorption effect in crystals. In Fig. 1 the functions for a g220 diffraction vector and t = 0.53 and 1.0 μm are shown. Here n= Θ‒ΘB, where Θ is the angle between the incident ray and the (hkl) planes, and ΘB is the Bragg angle.

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