Controlled thermal cleavage of optical glass by strontium-vapor laser radiation was studied. It was shown that high-quality complete separation of display glass is determined by the multiwave spectrum of the absorbed radiation. Sr-Laser radiation (λ = 6.45 μm) absorbed in a about 200 μm thick ‘top’ layer forms a surface microcrack, just as in the case of CO2 laser radiation (10.6 μm). Radiation in the about 1 and 3 μm range forms a ‘volume’ microcrack. Together these cracks create an additional effect making it possible to increase in the periodic-pulse regime the rate and quality of the laser separation of optical glass at comparatively low average lasing power.