Beschreibung:
<jats:title>Abstract</jats:title><jats:p>The Green's function method has been used to investigate the optical activity in the impurity absorption region of solids, taking account of anharmonicity. The host crystal containing the impurity centres is assumed to be optically non‐active. It is shown that the dependence of the optical rotation on the frequency of the exciting light is the same as that of the refractive index of the impurity centres, and the frequency dependence of the circular dichroism is the same as that of the absorption coefficient.</jats:p>