Editing Circular polarization (section)

==Luminescence==
''Circularly polarized luminescence'' (CPL) can occur when either a [[luminophore]] or an ensemble of luminophores is [[Chirality (chemistry)|chiral]]. The extent to which emissions are polarized is quantified in the same way it is for [[circular dichroism]], in terms of the ''dissymmetry factor'', also sometimes referred to as the ''[[anisotropy]] factor''. This value is given by:

:<math> g_{em} \ =\  2\left ( {\theta_\mathrm{left} - \theta_\mathrm{right} \over \theta_\mathrm{left} + \theta_\mathrm{right} } \right )   </math>

where <math> \theta_\mathrm{left} </math> corresponds to the quantum yield of left-handed circularly polarized light, and <math> \theta_\mathrm{right} </math> to that of right-handed light. The maximum absolute value of ''g''<sub>em</sub>, corresponding to purely left- or right-handed circular polarization, is therefore 2. Meanwhile, the smallest absolute value that ''g''<sub>em</sub> can achieve, corresponding to linearly polarized or unpolarized light, is zero.