Nested optical band gaps for a cholesteric elastomer slab under stress

Using the equilibrium configuration adopted by a cholesteric elastomer elongated by the influence of a uniaxial transverse stress, the authors calculate the solution of the boundary-value problem for the reflection and transmission of obliquely incident plane waves due to a elastomer slab. The authors find a left-circularly polarized thin reflection band immersed in a wider right-circularly polarized band reflection when the elastomer is under a stress near to the critical value. Also, a deformation of the reflection band and the reduction of its bandwidth were obtained. These band gap features suggest to design a finely tuning polarization-universal optical filter.