New transparent birefringent material for interference polarizer fabrication

Abstract

We have developed new clear birefringent material for interference polarizer (I-Polar) fabrication. I-Polar can be used in backlight recycling systems aimed to improve LCD light efficiency and reduce power consumption of the displays. We produced anisotropic films by wet coating of the new material onto a substrate with thickness in the range of 60-90 nm. Such thickness range meets the requirement for optical thickness of layers in the interference polarizer to be equal to the quarter ofa wavelength. One birefringent layer of the material coated on glass reflects 12% of polarization orthogonal to the anisotropic film coating direction (refraction index - 1.8) and a stack of 5 layers (3 birefringent layers alternated with 2 isotropic ones, refractive index of the isotropic material is equal to low index of birefringent layer) reflects 31% of the said polarization. We present design ofi-polar for typical LCD backlight spectrum.