title: Multiline resonant filters fashioned with different periodic subwavelength gratings.
abstract: We present the potential realization of multiline optical filters by the integration of different periodic gratings, which are implemented on an HfO₂-on-silicon platform. Supporting arms are used to manage the relief of residual stress to obtain freestanding HfO₂ gratings. The spectral properties are calculated by the rigorous coupled wave analysis method and measured by angular-resolved microreflectance. Multiple symmetric double resonances occur at the normal incidence, and asymmetric double resonances, which are attributed to the superposition of guided-mode resonances caused by different periodic gratings, are clearly observed under the off-normal incidence. The experimental results indicate that our proposed grating structures are promising for the realization of multiline filters.
authors.forename: Xumin
authors.initials: X
authors.lastname: Gao
authors.forename: Zheng
authors.initials: Z
authors.lastname: Shi
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhu
authors.forename: Yongjin
authors.initials: Y
authors.lastname: Wang