Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures

Abstract We investigated an asymmetric slab grating structure to achieve significant tuning of the quality (Q) factor for a leaky mode while minimizing frequency variation. This structure comprises two identical gratings placed on the top and bottom of a slab waveguide, with one grating laterally sh...

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Main Authors: Hyeon Sang Bark, Seong-Han Kim, Young Bin Ji, Jae Gwang Kwon, Chul Kang, In Hyung Baek, Kitae Lee, Seung Jae Oh, Tae-In Jeon, Chul-Sik Kee
Format: Article
Language:English
Published: Nature Portfolio 2024-12-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-024-80501-3
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author Hyeon Sang Bark
Seong-Han Kim
Young Bin Ji
Jae Gwang Kwon
Chul Kang
In Hyung Baek
Kitae Lee
Seung Jae Oh
Tae-In Jeon
Chul-Sik Kee
author_facet Hyeon Sang Bark
Seong-Han Kim
Young Bin Ji
Jae Gwang Kwon
Chul Kang
In Hyung Baek
Kitae Lee
Seung Jae Oh
Tae-In Jeon
Chul-Sik Kee
author_sort Hyeon Sang Bark
collection DOAJ
description Abstract We investigated an asymmetric slab grating structure to achieve significant tuning of the quality (Q) factor for a leaky mode while minimizing frequency variation. This structure comprises two identical gratings placed on the top and bottom of a slab waveguide, with one grating laterally shifted to introduce asymmetry. Simulations demonstrate that lateral shifting of one grating induces extensive changes in the Q-factor with minimal frequency variation, particularly near the band-flip filling fraction because the band-flip filling fraction remains unaffected by the shifting. The independence of the band-flip filling fraction from lateral shifting is attributed to the superposition property of Bragg scattering processes in the asymmetric grating structure. Experimental verification in the terahertz range confirms significant control over the Q-factor of the leaky mode of the structure. The proposed asymmetric slab grating structure offers possibilities for mechanically controllable optical devices, which are applicable to tunable filters and sensors. This study advances our understanding and application of leaky modes in asymmetric grating structures, revealing a previously unexplored aspect of asymmetric optical lattice.
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institution Kabale University
issn 2045-2322
language English
publishDate 2024-12-01
publisher Nature Portfolio
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series Scientific Reports
spelling doaj-art-f1362e141b2e401985718b60b06bcc942024-12-08T12:29:04ZengNature PortfolioScientific Reports2045-23222024-12-0114111010.1038/s41598-024-80501-3Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structuresHyeon Sang Bark0Seong-Han Kim1Young Bin Ji2Jae Gwang Kwon3Chul Kang4In Hyung Baek5Kitae Lee6Seung Jae Oh7Tae-In Jeon8Chul-Sik Kee9Divison of Applied Photonics System Research, Advanced Photonics Research Institute, GISTDivison of Applied Photonics System Research, Advanced Photonics Research Institute, GISTDivison of Applied Photonics System Research, Advanced Photonics Research Institute, GISTDivison of Applied Photonics System Research, Advanced Photonics Research Institute, GISTDivison of Applied Photonics System Research, Advanced Photonics Research Institute, GISTRadiation Center for Ultrafast Science, Korea Atomic Energy Research InstituteRadiation Center for Ultrafast Science, Korea Atomic Energy Research InstituteMedical Convergence Research Institute, Yonsei University College of MedicineElectrical and Electronics Engineering, Korea Maritime and Ocean UniversityDivison of Applied Photonics System Research, Advanced Photonics Research Institute, GISTAbstract We investigated an asymmetric slab grating structure to achieve significant tuning of the quality (Q) factor for a leaky mode while minimizing frequency variation. This structure comprises two identical gratings placed on the top and bottom of a slab waveguide, with one grating laterally shifted to introduce asymmetry. Simulations demonstrate that lateral shifting of one grating induces extensive changes in the Q-factor with minimal frequency variation, particularly near the band-flip filling fraction because the band-flip filling fraction remains unaffected by the shifting. The independence of the band-flip filling fraction from lateral shifting is attributed to the superposition property of Bragg scattering processes in the asymmetric grating structure. Experimental verification in the terahertz range confirms significant control over the Q-factor of the leaky mode of the structure. The proposed asymmetric slab grating structure offers possibilities for mechanically controllable optical devices, which are applicable to tunable filters and sensors. This study advances our understanding and application of leaky modes in asymmetric grating structures, revealing a previously unexplored aspect of asymmetric optical lattice.https://doi.org/10.1038/s41598-024-80501-3
spellingShingle Hyeon Sang Bark
Seong-Han Kim
Young Bin Ji
Jae Gwang Kwon
Chul Kang
In Hyung Baek
Kitae Lee
Seung Jae Oh
Tae-In Jeon
Chul-Sik Kee
Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures
Scientific Reports
title Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures
title_full Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures
title_fullStr Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures
title_full_unstemmed Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures
title_short Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures
title_sort extensive q factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures
url https://doi.org/10.1038/s41598-024-80501-3
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