  One notable feature of dye doped cholesteric liquid crystal is the variation
of pitch and refractive index as the incidence angle of the pumping light
shifts. Based on this feature, this paper studies the effects of pumping
light's incidence angle on emission properties of the dye doped cholesteric
liquid crystal tunable laser. First, we investigated the relationship among the
concentration of chiral reagent, the incidence angle of the pumping light, and
the pitch of liquid-crystal display (LCD); then we made a tunable-wavelength
laser and pumped the prepared sample with 532nm laser outputted from the Nd:
YAG multi-frequency pulse laser. As the incident angle of the pumping light
shifts between 20 {\deg} ~ 90 {\deg}, the tuning range of the wavelength
emitted by the laser reaches 10.73nm, ranging between 647.38nm and 658.11nm.
