title: Broadband high reflectivity in subwavelength-grating slab waveguides.
abstract: We computationally study a subwavelength dielectric grating structure, show that slab waveguide modes can be used to obtain broadband high reflectivity, and analyze how slab waveguide modes influence reflection. A structure showing interference between Fabry-Perot modes, slab waveguide modes, and waveguide array modes is designed with ultra-broadband high reflectivity. Owing to the coupling of guided modes, the region with reflectivity R > 0.99 has an ultra-high bandwidth (Δf / ̅f > 30%). The incident-angle region with R > 0.99 extends over a range greater than 40°. Moreover, an asymmetric waveguide structure with a semiconductor substrate is studied.
authors.forename: Hao
authors.initials: H
authors.lastname: Tian
authors.forename: Xuan
authors.initials: X
authors.lastname: Cui
authors.forename: Yan
authors.initials: Y
authors.lastname: Du
authors.forename: Peng
authors.initials: P
authors.lastname: Tan
authors.forename: Guang
authors.initials: G
authors.lastname: Shi
authors.forename: Zhongxiang
authors.initials: Z
authors.lastname: Zhou