We demonstrate the photoinduced phase transition and reversible switching of a cholesteric liquid crystal (CLC) doped with a high concentration of azobenzene LC (azo-LC). The photoinduced isotropic (PHI) state (light "ON") is created by the irradiation of a 405 nm laser, which generates cis-isomers that destabilize the cholesteric phase and make the LC transmissive. The response time is reduced by increasing the concentration of the doped azo-LC (<10 sec with 15 wt% azo-LC doped sample). A second light source of longer wavelength can be used to initiate a cis-to-trans photoisomerization of azobenzene. However, when a second light source is not used, the isotropic-to-cholesteric phase transition typically takes a long period of time (> 2 hr) for the cis-to-trans thermal isomerization reaction. We demonstrate a rapid (<10 sec) isotropic-to-cholesteric phase transition in a 10 wt% azo-LC doped sample without the use of a second light source. The phototunable cholesteric-isotropic phase transitions of azo-LC doped CLCs are reversible and repeatable. LC alignment is unnecessary in our highly concentrated azo-LC doped CLC recipes. Our study advances the research of optically switchable photonic devices based on LC materials.