Patent ID: 6867888

Claim:
A wavelength selective optical element comprising: a first polymer-dispersed liquid crystal switchable holographic component for diffracting a first wavelength of an incident beam wherein, a second wavelength of the incident beam passes through the first polymer dispersed liquid crystal switchable holographic component without being diffracted thereby; and a second polymer-dispersed liquid crystal switchable holographic component for diffracting the second wavelength, wherein the first and second polymer-dispersed liquid crystal switchable holographic components are located in stacked relationship with one another and placed in the path of the incident beam, wherein each of the first and second polymer-dispersed liquid crystal switchable holographic components is made by exposing an interference pattern inside a polymer-dispersed liquid crystal material, the polymer-dispersed liquid crystal material comprising, before exposure: (a) a polymerizable monomer; (b) vinyl neononanoate; (c) a liquid crystal; (d) a coinitiator; and (e) a photoinitiator dye.