In the Bragg wavelength regime, a sculptured thin film with chiral micromorphology permits light of a particular circular polarization state to pass virtually unhindered, but light of the other polarization state is reflected almost completely. On cascading two such films, but with one film twisted with respect to the other by an angle of 90 °, a hole appears in the reflection spectrum. This is proved theoretically as well as experimentally in this paper. Also, it is shown that the design wavelength of the filter can be tuned by a modest amount by tilting the filter with respect to the incident beam.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering