High-Performance Vector Polarizer Tailors Light

A proposed design for a vector polarizer could enable flexible filtering of a wide range of light sources and the generation of new light states. The design can be used to tailor light intensity, phase and polarization.

To increase polarizer efficiency and flexibility, researchers from Nanjing and Nankai Universities and the University of Central Florida used a liquid-crystal-based design that relies on birefringence. Using a birefringent mechanism, the team’s vector polarizer spatially separates orthogonally polarized ordinary and extraordinary beams. The specific polarizations are filtered based on their refractive indexes.

Researchers customized the orientation of liquid crystal molecules using stringent photo-alignment techniques. They determined the dichroic dye film structure within a thin glass compartment before adding the liquid crystal.

The high-performance broadband vector polarizer could be used to flexibly tailor the polarization structures and the intensity patterns of optical fields. It could also act as a high-efficiency generator of vector optical fields (VOF).

“An enormous challenge was how to solve the design and fabrication of vector polarizers to tailor the light beams and satisfy the requirements of various applications,” said researcher Hui-Tian Wang. “The vector polarizer can significantly improve the generation efficiency of vector light beam and may be conducive to achieving a high-performance vector laser.”

The new vector polarizers could offer manufacturing advantages as well.

“They are flexibly designed and easily fabricated, and have the advantages of the large-size complex structures and the broadband (light waves) operation,” Wang said.

“However, the vector polarizer we proposed still needs some improvements. For example, we need to improve its alignment quality, i.e., the quality of generated light beams. We also need to improve the spatial resolution for controlling the orientation of liquid crystal molecules,” he said.

Wang is particularly excited about this vector polarizer’s ability to generate new polarized light states, which he hopes to use in developing novel applications. As an example, entangled vector photon states could be used in developing technology for quantum communications.

The research was published in APL Photonics (doi: 10.1063/1.5006016).