Design of broadband highly reflective subwavelength high-index-contrast gratings in the visible regime

• DOI: 10.1364/osac.389931
• Publication Date: 2020-04-22T03:00:08Z
• Authors: Xingzhe Shi; Yuanfu Lu; Changshui Chen; Songhao Liu; Guangyuan Li
• Keywords: High contrast; Visible spectrum

We report the design of broadband highly reflective subwavelength high-index-contrast gratings (HCGs) for both TE and TM polarizations in visible regime. Results show that high reflectivity above 99% covering 544–726 nm or 510–666 can be achieved, corresponding to a fractional bandwidth Δ λ / 0 = 28.7% 26.5% polarization, respectively. reveal these broad high-reflectivity bands originate from blend multiple leaky modes, similar counterparts operating near-infrared By investigating effects grating height, period, width, we find requires careful optimization. expect this work will advance engineering HCG reflectors promote their applications