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Normal incidence filters using symmetry-protected modes in dielectric subwavelength gratings.

ABSTRACT: We investigate narrowband transmission filters based on subwavelength-grating reflectors at normal incidence. Computational results show that the filtering is realized through symmetry-protected mode coupling. The guided mode resonances introduced by the slab layer allow flexible control of the filter frequencies. The quality factor of the filters could exceed 10⁶. Dielectric gratings can be used over the entire range of electromagnetic waves, owing to their scale-invariant operations. Owing to the high refraction index and low index dispersion of semiconductors in the infrared range, these filters can be applied over a broad range from near infrared to terahertz frequencies.

SUBMITTER: Cui X

PROVIDER: S-EPMC5099914 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature

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Normal incidence filters using symmetry-protected modes in dielectric subwavelength gratings.

Cui Xuan X Tian Hao H Du Yan Y Shi Guang G Zhou Zhongxiang Z

Scientific reports 20161108

We investigate narrowband transmission filters based on subwavelength-grating reflectors at normal incidence. Computational results show that the filtering is realized through symmetry-protected mode coupling. The guided mode resonances introduced by the slab layer allow flexible control of the filter frequencies. The quality factor of the filters could exceed 10<sup>6</sup>. Dielectric gratings can be used over the entire range of electromagnetic waves, owing to their scale-invariant operations ...[more]

PMID: 27824049

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