Silicon phosphate-based optical glass and method for preparing bismuth-doped

The invention provides bismuth-doped silicophosphate-based optical glass and a preparation method thereof. The preparation method comprises the following steps of: uniformly mixing the following components in percentage by mole: 34.9-64.9 percent of SiO2, 8-20 percent of P2O5, 15-35 percent of Al2O3, 15-45 percent of RO and/or RCO3 and 0.1-5 percent of Bi2O3; heating the mixture to 1,300-1,600 DEG C, preserving heat for 30-180 minutes and melting the raw material to be in a liquid state; and annealing at 500-650 DEG C for 0.5-6 hours, and naturally cooling to room temperature to obtain the bismuth-doped silicophosphate-based optical glass. The bismuth-doped silicophosphate-based optical glass has the ultra-broadband optical performance of covering an entire communication waveband, the melting temperature is remarkably lowered relative to quartz glass, and the viscosity of the melting liquid in the melting process of the glass is lowered, so that the defects (such as air bubbles and the like) in the melting and molding processes of the glass are reduced compared with those of quartz glass, the mechanical performance of the glass is improved, and infrared illumination intensity of bismuth in the glass is high.