Phase-retarders or waveplates are optics that affect the polarization state of light. They have several applications including 3D glasses, optical pickup drives, holography, etc. Many of these applications require control of polarization properties across a certain wavelength range. We have developed Multi-Twist Retarders (MTRs) as means to easily accomplish this at low cost. MTRs are stacks of self-aligned liquid crystal twist layers, precisely tuned to produce the desired optical properties. In the figure below, a broadband MTR (for 3D glasses) produced in our lab and a commercial waveplate are compared, and the performance is very similar.
A second example is shown below where a different MTR is patterned to produce different colors in different zones. The picture was taken with polarized light and there is a second polarizer on the camera that differentiates the colors. This is an example of color fitler application for MTRs.