Table 1.

Terms and definitions in chiroptical spectroscopy.

Type	Acronym	Definition
Optical rotation	α	The rotation of linearly polarized light as it travels through certain non-racemic materials.
Optical rotatory dispersion	ORD	The variation in the specific rotation of a substance with a change in the wavelength of light. May be used to determine the absolute configuration of metal complexes, for example.
Circular dichroism	CD	A form of spectroscopy based on the differential absorption (Δε) of left- and right-handed circularly polarized light (LCP and RCP) in non-racemic molecules.
Exction-coupled circular dichroism(Exciton Chirality)	ECCD	Circular dichroism coming from an exciton couplet: Two chromophores presenting in a molecule in close proximity to one another, who interact and give rise to differentiation of the energies of the transitions.
Fluorescence-detected CD	FDCD	Circular dichroism derived from the differential emission of light from a sample excited with LCP and RCP radiation when the analyte is chiral, fluorescent, and the quantum yield is the same for both circularly polarized components.
Diffrentialcircularly polarized fluorescence excitation	CPE(ΔF)	The differential emission of light from a sample excited with LCP and RCP radiation. The quantum yield does not have to be the same for both circularly polarized components
Circularly polarized luminescence	CPL	The anisotropic emission of circularly polarized light originated from non-polarized excitation.