An optical element comprises a fluorescence luminous element that emits
fluorescent light when excited and a cholesteric filter disposed at the
incident side of the fluorescence luminous element at which excitation
light enters the fluorescence luminous element. The cholesteric filter
comprises a cholesteric layer operative to transmit the excitation light
and to reflect backward scattered fluorescent light traveling thereto so
as to be integrated with fluorescent light directly coming out of the
cholesteric filter.
