ALKALINE METAL DOPANTS AND PHOTODARKENING IN COLORED FILTER GLASS

It is clearly shown for the first time that alkaline metal ions assist the photodarkening effect in colored filter glass. Time responses of samples vary depending on the kind of alkaline metal dopants involved as additive compounds for improving glass quality. Energy relaxation t imes of photoexcited carriers after laser beam irradiation change foll owing weight quotients of potassium oxides from sodium oxides. The fas test response after irradiation can be obtained when the quotient is a pproximately two. This quotient corresponds to compositions showing co nspicuous mixed-alkali effects from potassium and sodium.