Porous glasses as a host for solid state tunable lasers in the visible as a means for fluorescence diagnostics and photodynamic therapy.

Lasers prepared by incorporation of the active dyes into porous glasses are described. The background of the use of lasers for photodynamic therapy and diagnostics is outlined. The role of hematoporphyrin and hypericin in creation of singlet oxygen which destroys the malignant tissues, is explained. The lasers, based on sol-gel technology, incorporated by several perylimide and pyrromethane dyes emit in the suitable range in which the hematoporphyrin is excited. These compact lasers may replace, in the future, the vapour and the liquid lasers. The synthesis and the spectroscopic properties of the laser are described.