Abstract: A method of producing a polarizing glass article that exhibits a broad band of high contrast polarizing properties in the infrared region of the radiation spectrum. The polarizing glass is phase-separated or exhibits photochromic properties based on silver, copper, or copper-cadmium halide crystals or a combination thereof, which are precipitated in the glass and having a size in the range of 200-5000 Å. The glass has a surface layer containing elongated silver, copper, or copper cadmium metal particles, or a mixture thereof. The method comprises subjecting the glass article to a time-temperature cycle in which the temperature is at least about 76° C. or greater above the glass softening point, in a step to thermally form and precipitate large halide crystals, and elongated metallic particles under a stress of not over about 3000 psi, preferably not over about 2675 psi.

Abstract: A method of producing a polarizing glass article that exhibits a broad band of high contrast polarizing properties in the infrared region of the radiation spectrum. The polarizing glass is phase-separated or exhibits photochromic properties based on silver, copper, or copper-cadmium halide crystals or a combination thereof, which are precipitated in the glass and having a size in the range of 200-5000 Å. The glass has a surface layer containing elongated silver, copper, or copper cadmium metal particles, or a mixture thereof. The method comprises subjecting the glass article to a time-temperature cycle in which the temperature is at least about 76° C. or greater above the glass softening point, in a step to thermally form and precipitate large halide crystals, and elongated metallic particles under a stress of not over about 3000 psi, preferably not over about 2675 psi.