Polarization filters with an autocloned symmetric structure

The process of fabricating photonic crystals comprised of alternately stacked high- and low-index dielectric materials on periodic substrates to form zigzag films is called the autocloning technique. In this study, we have fabricated TiO2/SiO2 two-dimensional polarization filters by using electron beam gun evaporation with ion-beam-assisted deposition. The shape of the zigzag structure is preserved, and the total thickness is 8 μm. The symmetric structural design can be utilized as an antireflection coating applied to reduce ripples and achieve a 200 nm working wavelength range.