The polarization of colorPol®® polarizers is caused by elongated silver nano particles, which are embedded into the glass only in a shallow depth. This specific design offers the possibility to remove these nano particles by surface etching. With lithography, this can be done selectively.
A patterned polarizer with regions of either transparent or linear polarizing properties is the result. The shape of the regions can be randomly chosen, the resolution can be as high as 30 µm at still reasonable costs. The polarization axis of all regions as well as the wavelength range is same.
To create a polarizer with regions of different polarization axes, at least two of the polarizers, which were patterned as described above, must be stacked on top of each other (see sketch above). The more different orientations of the polarization axis are needed, the more planes must be stacked. The different height positions of the planes may cause a parallax.
If used as an analyzer, the scattering of the nano particles may lead to a decrease of the polarizers contrast and some crosstalk in rare cases.
