Near-Simultaneous Observations of a Geosynchronous Satellite Using Two Telescopes and Multiple Optical Filters

Hexagonal boron nitride (hBN) exhibits natural hyperbolic dispersion in the infrared (IR) wavelength spectrum. In particular, the hybridization of its hyperbolic phonon polaritons (HPPs) and surface plasmon resonances (SPRs) induced by metallic nanostructures is expected to serve as a new platform for novel light manipulation. In this study, the transmission properties of embedded hBN in metallic one-dimensional (1D) nanoslits were theoretically investigated using a rigorous coupled wave analysis method. Extraordinary optical transmission (EOT) was observed in the type-II Reststrahlen band, which was attributed to the hybridization of HPPs in hBN and SPRs in 1D nanoslits. The calculated electric field distributions indicated that the unique Fabry–Pérot-like resonance was induced by the hybridization of HPPs and SPRs in an embedded hBN cavity. The trajectory of the confined light was a zigzag owing to the hyperbolicity of hBN, and its resonance number depended primarily on the aspect ratio of the 1D nanoslit. Such an EOT is also independent of the slit width and incident angle of light. These findings can not only assist in the development of improved strategies for the extreme confinement of IR light but may also be applied to ultrathin optical filters, advanced photodetectors, and optical devices.

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Polymer Dispersed Cholesteric Liquid Crystals With a Toroidal Director Configuration under an Electric Field

Polymers ◽

10.3390/polym13050732 ◽

2021 ◽

Vol 13 (5) ◽

pp. 732

Author(s):

Anna P. Gardymova ◽

Mikhail N. Krakhalev ◽

Victor Ya. Zyryanov ◽

Alexandra A. Gruzdenko ◽

Andrey A. Alekseev ◽

...

Keyword(s):

Optical Properties ◽

Liquid Crystal ◽

Electric Field ◽

Point Defects ◽

Structural Response ◽

Optical Filters ◽

Response Curves ◽

Polymer Dispersed Liquid Crystal ◽

Dichroic Dye ◽

Polymer Dispersed

The electro-optical properties of polymer dispersed liquid crystal (PDLC) films are highly dependent on the features of the contained liquid crystal (LC) droplets. Cholesteric LC droplets with homeotropic boundaries can form several topologically different orientational structures, including ones with single and more point defects, layer-like, and axisymmetric twisted toroidal structures. These structures are very sensitive to an applied electric field. In this work, we have demonstrated experimentally and by computer simulations that twisted toroidal droplets reveal strong structural response to the electric field. In turn, this leads to vivid changes in the optical texture in crossed polarizers. The response of droplets of different sizes were found to be equivalent in terms of dimensionless parameters. In addition, the explanation of this phenomenon showed a comparison of theoretical and experimental structural response curves aids to determine the shape of the droplet. Finally, we demonstrated that the addition of a dichroic dye allows such films to be used as optical filters with adjustable color even without polarizers.

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