| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the subject glass imparted with second harmonic generation function by designing the preform thereof to have a specified composition comprising GeO2, B2O3, La2O3 and Gd2O3. SOLUTION: This transparent crystallized glass is such one that the preform thereof comprises 10-70 mol% of GeO2, 10-50 mol% of B2O3, 15-35 mol% of La2O3 and 0-10 mol% of Gd2O3, being obtained by heat treatment of the preform to effect deposition of Stillwellite-type LaBGeO5 crystal on the surface; wherein the above crystal has considerably high second harmonic generation function, therefore meaning that this transparent crystallized glass has second harmonic generation function as well; the above hear treatment is pref. carried out in the following two steps: the preform is held at (Tg-10) to (Tg+10) deg.C for 2-4 h and then at (Tc-110) to (Tg-90) deg.C for 4-6 h (where, Tg is the glass transition temperature of the preform; Tc is the crystallization beginning temperature of the preform).</p> |
