OPTICAL GENERATION OF BRAGG GRATINGS IN CERIUM-DOPED FLUORIDE GLASSES

掺铈氟化物玻璃中布拉格光栅的光学产生

• 批准号: 09650003
• 负责人: SUZUKI Yoshiro
• 金额: $ 1.41万
• 依托单位: MIYAGI NATIONAL COLLEGE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650003/
• 关键词: aluminum fluoride; Bragg grating; cerium; UV exposure; photochromism; absorption; index change

Photo-generation of Bragg grating in glass matrixes has received much attention as a key technology to assemble optical fibers and waveguides. To extend the validity of this technique, it is important to search for photo-writable system in a variety of glass materials. This is required especially in fluoride glasses because of their superiority as optical gain media. We have sensitized aluminum fluoride glasses (AFG) with cerium ions and evaluated their applicability to Bragg grating media. Samples examined were multicomponent AFG plates with the composition of 34.5A1F_3, 13.5YF_3, 52 (Mg+Ca+Sr+Ba) F_2 in mol%. The concentration of CeF_3 ranged 0.05 to 4.Omol%. The dipole-allowed 4f-5d transitions of the trivalent cerium ions (Ce^<3+>) yielded intense absorption bands at 4.5 to 6.5eV.Exposure to 5.00eV light from a KrF laser (46mJ/cm^2shot) caused a fractional bleach of the Ce^<3+> bands and growths of two new bands peaking at 3.8 and 6.2eV, The both bands increased in proportion to the Ce^3 concentration and the exposure dose, which suggests that the photo-induced valence change of the Ce^<3+> ions attributes the absorption changes. The 6.2eV band increased monotonously with the accumulation of the laser exposure up to 20000 shots, while the 3.2eV band saturated at the exposure of 200 shots, From the Kramers-Kronig relation, the maximum refractive index change was estimated to be 2.7X10^<-5>. Isochronal annealing measurements showed the 3.8eV band is almost stable up to 1000C, while the 6.2eV band up to 3000ﾟC.These results suggest that the cerium-doped AFG have a potential for Bragg grating media.

作为光纤和波导组装的关键技术之一，布拉格光栅在玻璃基体上的光产生受到了广泛的关注。为了扩展该技术的有效性，在各种玻璃材料中寻找光可写系统是很重要的。由于氟化物玻璃作为光学增益介质的优越性，尤其需要这样做。用铈离子敏化氟化铝玻璃（AFG），并对其在布拉格光栅介质中的适用性进行了评价。样品为多组分AFG板，组成为34.5A1F_3, 13.5YF_3, 52 (Mg+Ca+Sr+Ba) F_2 （mol%）。CeF_3浓度范围为0.05 ~ 4.mol %。三价铈离子（Ce^<3+>）的偶极允许4f-5d跃迁产生了4.5 ~ 6.5eV的强吸收带。在5.00eV的KrF激光（46mJ/cm^2）照射下，Ce^<3+>离子的谱带出现了部分漂白，并出现了两个新的谱带，分别在3.8和6.2eV处出现峰值，这两个谱带随Ce^3浓度和照射剂量的增加而增大，表明Ce^<3+>离子的价态变化与吸收变化有关。6.2eV波段随着曝光次数的增加而单调增加，而3.2eV波段在曝光次数达到200次时达到饱和，根据Kramers-Kronig关系，估计最大折射率变化为2.7X10^<-5>。等时退火测试表明，3.8eV波段在1000℃下基本稳定，而6.2eV波段在3000℃下基本稳定。这些结果表明，掺铈AFG具有作为布拉格光栅介质的潜力。

项目成果

Y.SUZUKI,T.SAKUMA AND M.HIRAI: "UV EMISSION FROM THE LOWEST 5d STATE IN Ce^<3+> : YAG" Material Science Forum. 239-241. 219-241 (1997)

Y.SUZUKI、T.SAKUMA 和 M.HIRAI：“Ce^<3 > 中最低 5d 状态的紫外线发射：YAG”材料科学论坛。

Y.Suzuki,T.Sakuma and M.Hirai: "UV Emission from the Second Lowest 5d State in Ce^<3+>:YAG" Materials Science Forum. 239-241. 219-222 (1997)

Y.Suzuki、T.Sakuma 和 M.Hirai：“Ce^<3 > 中第二最低 5d 态的 UV 发射：YAG”材料科学论坛。

Y.Kondo,Y.Suzuki, K.Shimoyama and M.Yanagihara: "F-Center Formation by K-Shell Excitation in KBr,RbCl and KI" Materials Science Forum. 239-241. 587-590 (1997)

Y.Kondo、Y.Suzuki、K.Shimoyama 和 M.Yanagihara：“KBr、RbCl 和 KI 中 K 壳层激发形成 F 中心”材料科学论坛。

Y.KONDO,Y.SUZUKI,K.SHIMOYAMA AND M.YANAGIHARA: "F-CENTER FORMATION BY K-SHELL EXCITATION IN KBr, RbBr AND KI" Material Science Forum. 239-241. 587-590 (1997)

Y.KONDO、Y.SUZUKI、K.SHIMOYAMA 和 M.Yanagihara：“KBr、RbBr 和 KI 中 K 壳层激发形成 F 中心”材料科学论坛。