Temporary Bleaching of the M Band in KBr ana KCl

Abstract

Temporary bleaching of color centers in additively colored KBr and KCl crystals are investigated. The first and the second absorption bands of M center are bleached by F-light or M-light irradiation at 90°K. Accompanying with the bleaching of the M band, two absorption bands grow at 555 mμ and 780 mμ in KBr and at 505 mμ and 690 mμ in KCl. These bands as well as the bleached M bands show dichroism when the original M band is dichroic. The oscillator strengths of these bands are determined with respect to the M band, and discussions on the nature of the bands are made.