14. Principles and Applications of Circularly Polarized Luminescence Spectrophotometer

Materials that exhibit circularly polarized light characteristics are finding an increasing range of applications, such as liquid crystal display backlights, three-dimensional displays, holographic displays, plant growth control illumination, security systems for optical communications, and printing. In this chapter, we will describe the basic principles of circularly polarized luminescence (CPL) spectroscopy, the instruments used to measure CPL signals, including optical systems and signal acquisition methods in commercially available CPL instruments, and also methods for calibrating such equipment. Example measurements are presented for camphor and camphorquinone, which are long-established CPL samples, in addition to lanthanoid complexes that are promising CPL luminescent materials, biopolymers that are highly sensitive to circularly polarized light, and solid samples that have been attracting attention in recent years.