Effect of external stresses on the optical absorption ofU2-centers in alkali-halides

An electric dipole transition model is used to investigate the influence of applied external stresses on the optical absorptionband of U2-centers in alkali-halides. An analysis of the effect can be made by the method of moments. The results are similar to what happens in the case of aF-center, except that the Γ4-mode must also be taken into account.