Patterned liquid crystal polymer C-plate retarder and color polarizer

The patternability and guest–host interaction with dichroic dye and C-plate liquid crystal polymer (LCP) materials are investigated, and the optical properties of a thin film C-plate retarder and polarizer are studied and compared with theory. The C-plate retarder is a waveplate made of a uniaxial LCP where the optical axis of the LCP is parallel to the surface normal of the optic. No retardance is observed at a normal angle of incidence and retardance grows as the angle of incidence increases. The C-plate polarizer is a C-plate retarder with LCP as the host and a dichroic dye as the guest. The linear diattenuation (LD) of the linear polarizer is zero at a normal angle of incidence and grows with an increasing angle of incidence. Both the C-plate retarder and polarizer can be patterned with minimum feature size down to 2 µm by using ultraviolet photolithography and plasma etching. A planarization process is also developed to deposit a cover layer on top of the pattern to reduce optical loss and to serve as a barrier for subsequent layers.