| 摘要 |
PURPOSE:To manufacture high quality porous glass with a small transmission loss by eluting phase separated glass with acid and eluting the inner surfaces of the resulting pores with a weakly alkaline soln. or an F<->-contg. soln. prior to collapsing. CONSTITUTION:The soft phase of phase separated glass is eluted with acid, and the glass is washed with an aqueous weak alkali soln. such as 0.1 NNa2CO3 or an F<->-contg. soln., washed with pure water prior to acid washing, and repeatedly washed with acid and an aqueous weak alkali soln. or an F<->-contg. soln. As a result, colloidal silica on the inner surfaces of the resulting pores are eluted together with the residual isolated soft phase on the surfaces. The glass is then dehydrated, degassed, and collapsed under an inert gas atmosphere or the like to obtain porous glass. CsNO3 or the like may be deposited on the inner surfaces of the pores prior to the dehydration. |
