Cholesteric liquid crystals (CLCs) have been extensively studied for application to new optical elements due to their excellent selective reflection of light. There have been various reports on how to broaden reflection band, such as pitch gradient distribution, but here we have developed a method for penetrating a high-birefringence guest liquid crystal after preparation of a CLC polymer film. It has been confirmed that the penetration of 5CT liquid crystal can broaden the selective reflection bandwidth by about 21% with increasing pitch-length of CLC. We will also report that this method can be applied to liquid crystal diffraction gratings.
