| 摘要 |
PURPOSE:To easily obtain a light-transmission glass material having a definite concentration gradient, by diffusion a dopant into a porous glass, developing a concentration distribution of the dopant and quenching the glass in a stage of fixing the concentration distribution. CONSTITUTION:A dopant is sufficiently diffused into a porous glass material and the dopant is eluted by immersing the glass in a solvent such as a mixture of alcohol and water to develop a concentration distribution of the dopant. The dopant concentration in the obtained glass has a gradient from the surface toward the inner part. The concentration distribution having the concentration gradient is fixed by quenching the porous glass material and the obtained material is dried and sintered to obtain the objective glass material having refractive index distribution. Since the porous glass material is quenched with liquid nitrogen or dry ice, etc., in the present process, the dopant in the porous material is precipitated at the existing place. Accordingly, the concentration distribution can be maintained in the quenched product. |
