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Optical physicists from Nanjing and Nankai University, China, and the University of Central Florida, U.S., have published details of their new vector polarizer design. The newly proposed design is a major advancement in polarization technology because it enables flexible filtering of a wide range of light sources and generation of new light states.

Light waves can oscillate with their back-and-forth motion oriented along different directions, where its polarization describes the nature of this orientation. A traditional polarizer, like a lens from polarized sunglasses, filters out light oscillating along all but one direction. The filtered light is referred to as polarized light.

The core challenge was how to solve the design and fabrication of vector polarizers to tailor the light beams and satisfy the requirements of various applications. The vector polarizer can significantly improve the generation efficiency of vector light beam and may be conducive to achieving a high-performance vector laser. These advancements can be used to improve a variety of optical systems. In super-resolution microscopy, for instance, manipulating polarization can be used to achieve far-field focusing beyond normal diffraction limitations.

The physicists increased polarizer efficiency and flexibility by using a new liquid-crystal-based design that relies on birefringence, where specific polarizations are filtered, based on their refractive indexes. The orientation of liquid crystal molecules were customised by using stringent photo-alignment techniques. They determined the dichroic dye film structure within the thin glass compartment before adding the liquid crystal.

The new vector polarizers also feature manufacturing advantages. They are flexibly designed and easily fabricated, and have the advantages of the large-size complex structures and the broadband [light waves] operation. However, the vector polarizer proposed still needs some improvements like alignment quality, the quality of generated light beams and the spatial resolution for controlling the orientation of liquid crystal molecules.