| 摘要 |
PURPOSE:To increase the transmissivity of the subject glass and to eliminate the 2,730nm absorption based on the OH stretching vibration by allowing the porous base material obtained by depositing fine SiO2 particles to react with a chlorinating agent, then removing the residual chlorinating agent and vitrifying the material. CONSTITUTION:Silicon halide (e.g. SiCl4) is hydrolyzed in a flame under the conditions where the flow rate ratio of H2 to O2 is controlled to 0.5-2.0 and that of H2 to silicon halide to 10-100, and the obtained fine SiO2 particles are deposited to obtain a porous base material. The base material is then allowed to react with a chlorinating agent (e.g. Cl2) at 1,000-1,300 deg.C. The reaction product is dehydrated, then heated at 1,000-1,300 deg.C to remove the residual chlorinating agent, and vitirfied at 1,450-1,550 deg.C. Consequently, the high-purity quartz glass having >=88% transmissivity in the 200-2,500nm wavelength region and without the 2,730nm absorption based on the OH stretching vibration is obtained. |
