A non-polarization short-wave-pass thin film edge filter

Abstract:

Multilayer dielectric thin film edge filter has serious polarization sensitivity under oblique incidence. The cutoff-bands of the s-polarization and p-polarization light in conventional edge filter will separate obviously under 45° oblique incidence, which limits its application. Based on the two chosen materials TiO₂ and SiO₂, a novel stack structure is proposed to design the non-polarization short-wave-pass thin film edge filter. By using the (4H 4L 4H) as the matching layers, the polarization separation at 3 dB transmittance for the thin film edge filter cutoff-band is less than 1 nm at the incident angle of 45°. In this way, the non-polarization short-wave-pass edge filter is easily designed and fabricated.