Giant Birefringence of Periodic Dielectric Waveguides

The giant
$(\Delta n \;>\; 1.5)$
and broadband achromatic birefringence is realized by periodic dielectric waveguides (PDWs), which benefit from low loss transmission, compact size, and simple structure. Based on the PDW, ultrabroadband achromatic (
$>$
100 nm), low-order ultracompact
$(<\ \lambda)$
, and ultrahigh-order (500th order) wave plates are designed successfully.