Luminescence-based circular polarization convertors: polarization conversion of linearly polarized photoluminescence from one-dimensionally aligned quantum rods using retardation films

Abstract

Existing methods for generating circularly polarized (CP) light from an unpolarized light source without using external electrical energy have drawbacks, such as a trade-off relationship between CP light intensity and purity. Here, we demonstrate an approach for the generation of high-purity, high-intensity CP light based on a luminescence-based CP convertor composed of a linearly polarized luminescence (LPL) film and a quarter-wave plate. The LPL films, fabricated by one-dimensional alignment of semiconductor quantum rods and laminated with a quarter-wave plate, enabled effective conversion of LPL to high-purity CP light and retained the photoluminescent spectral pattern, light intensity, and the large degree of polarization. The sign of CP light was easily switched by changing the orientation of the quarter-wave plate and the LPL polarization plane. Furthermore, we also demonstrate the first example of parallel-type and multi-layered luminescence-based CP light convertors for multiplexing optical information. Our findings will aid the design of next-generation CP light-generating materials.