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In this work, we theoretically propose and numerically demonstrate a novel multi-band subtractive filtering platform by utilizing the dielectric resonators. In addition, the plasmon-like hotspots are also observed in this dielectric structure. Multi-band light filtering can be quantitatively adjusted by the polarization state and the classical Malus law is verified in this dielectric structure. These findings lay a foundation for multispectral optical behaviors and hold applications in the nanophotonics. [ABSTRACT FROM AUTHOR]

Narrowband light absorbers are of great importance in many practical applications, such as color filtering and thermal emission. Here, we experimentally demonstrate a multispectral narrowband light absorber based on a silicon nano-cavity coupled metallo-dielectric cavity. Seven absorption bands with excellent absorption features are achieved in the near-infrared region. Theoretical results indicate that the multi-band light absorption strongly attributes to the hybridization coupling between the optical modes of the silicon cavity and the plasmonic resonances of the metallic structure. These optical features hold the absorber with wide applications in optoelectronics. • A novel narrowband light absorber is demonstrated in a silicon nano-cavity coupled metallo-dielectric structure. • The maximal absorbance above 94% and bandwidth less than 21 nm are achieved. • Ultra-narrow bandwidth down to single-digit level (4 nm) is achieved in the calculation. • This absorber can be fabricated in large-area at low-cost by the standard technique. [ABSTRACT FROM AUTHOR]

Ultra-narrowband light filtering is with wide applications in display, image and optical measurement devices. Here, we theoretically propose and show a new and simple strategy for achieving notch filters by sub-wavelength all-dielectric meta-materials (ADMMs). The ADMM is comprised of a triple-layered high/low/high-index dielectric structure. Similar to the plasmonic resonances existed in the metallic meta-materials, strong optical field resonances have been observed in this ADMM. Dual-band reflective notch filtering phenomenon is achieved. Spectral bandwidth down to 3 nm and the spectral contrast reaching 97% are obtained. Moreover, the polarization-independent response is simultaneously achieved in this ADMM. Furthermore, high spectral tunability for the observed ultra-narrowband filtering is obtained via tuning the structural parameters. [ABSTRACT FROM AUTHOR]