Chiroptical properties induced in chiral photonic-bandgap liquid crystals leading to a highly efficient laser-feedback effect

Highly efficient lasing action is obtained by exploiting the chiroptical characteristics of the around and excited states of an achiral fluorescent dye doped in a cholesteric liquid crystal (CLC) medium (see figure). The highly efficient lasing action from the oblique dye-doped CLC cell is produced by tuning the ellipticity angle of the excitation beam while taking into consideration the molecular helical sense of the cholesteric host.