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Fabrication and optical characterization of near UV-laser crystals using low-symmetry crystal field

使用低对称性晶体场的近紫外激光晶体的制造和光学表征

基本信息

批准号：
10650659
负责人：
KODAMA Nobuhiro
金额：
$ 0.58万
依托单位：
AKITA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650659/
关键词：
Spectrocopy Crystal field Laser Single crystal Crystal growth Structure analysis

项目摘要

We have grown CeィイD13+ィエD1-doped fluorides [BaMgFィイD24ィエD2, CaNaYFィイD26ィエD2] and oxides [melilite-type crystals AィイD22ィエD2BィイD23ィエD2OィイD27ィエD2(A=Ca, Y ; B=Al, Si)] which are candidates for tunable laser materials in the near UV and violet regions. In order to widely spread phosphors in the UV and visible regions, we have studied the optical characterization of these crystal and the effects of the strength and low-symmetry of the crystal field in the associated anion coordination polyhedron. The results of this study are summarized as follows.1. The lowest energy and the center of the gravity of the ィイD12ィエD1D excited state energy levels may be explained by the nephelauxetic effect, lowering symmetry caused by distortion, and size of the annion-coordinate polyhedra of the CeィイD13+ィエD1 in fluoride and oxide crystals.2. Broad photoluminescence in the near UV and violet regions is observed in CeィイD13+ィエD1-doped melilite CaィイD22ィエD2AlィイD22ィエD2SiOィイD27ィエD2 and CaYAlィイD23ィエD2OィイD27ィエD2. The p … More hotoluminescence spectra for these crystals are inhomogeneously broadened by the substitutional disorder. The lowest peak energies of the absorption bands of CeィイD13+ィエD1 in those crystals are coincident with the third harmonic (355nm) of a YAG laser. A new phosphor CeィイD13+ィエD1-doped BaMgFィイD24ィエD2 crystal was grown. The different optical spectra of CeィイD13+ィエD1 in the UV region are assigned to be due to regular and perturbed CeィイD13+ィエD1 site in the crystal. The energy level of the lowest 5d excited state of CeィイD13+ィエD1 in the BaMgFィイD24ィエD2 crystal is coincident with the fourth harmonics (266nm) of a Nd : YAG laser.The BaMgFィイD24ィエD2 : CeィイD13+ィエD1 and CaィイD22ィエD2AlィイD22ィエD2SiOィイD27ィエD2 : CeィイD13+ィエD1 crystals are expected to be new laser materials with a high gain and wide tuning range between the UV and near UV regions.3. UV excitation or infrared femtosecond laser excitation of CeィイD13+ィエD1-doped melilite crystals CaィイD22ィエD2AlィイD22ィエD2SiOィイD27ィエD2 and CaYALィイD23ィエD2OィイD27ィエD2 produces long-lasting phosphorescence besides intrinsic CeィイD13+ィエD1 luminescence with short lifetime (40ns). The phosphorescence persists for not less than 1 h after removal of the irradiating light. The long-lasting phosphorescence may be explained by a model of electron-hole recombination at CeィイD13+ィエD1 sites caused by hopping motion, which occurs by a thermally activated process. This is first observation of long-lasting phosphorescence of CeィイD13+ィエD1. This new optical function will be useful in the fabrication of spontaneously disappearing image pattern and time-limited three-dimensional optical memory devices. Less

我们已经生长了Ce掺杂的D13+ Ce掺杂的D1-氟化物[BaMgF掺杂的D24 D2，CaNaYF掺杂的D26 D2]和氧化物[黄长石型晶体A掺杂的D22 B掺杂的D23 D2 O掺杂的D27 D2（A=Ca，Y ; B=Al，Si）]，它们是近紫外和紫色区域可调谐激光材料的候选者。为了使荧光粉在紫外和可见光区得到广泛的应用，我们研究了这些晶体的光学特性，以及负离子配位多面体中晶体场强度和低对称性的影响。本研究的结果总结如下. Ce_（12）Ce_（13）D_（13）+Ce_（12）D_（11）D_（11）激发态能级的最低能量和重心可以用云拉效应、畸变引起的对称性降低以及氟化物和氧化物晶体中Ce_（13）+Ce_（12）D_（11）D_（13）的annion-coordinate多面体的尺寸来解释。在Ce掺杂黄长石Ca YAl D22 Al 2 O3 D22 Al 2 O3 D27 Al 2 O3 D27 Al 2 O3 D2和Ca YAl Al 2 O3 D23 Al 2 O3 D27 Al 2 O3 D27 Al 2 O3 D27 Al 2 O3 D2中观察到近紫外和紫光区的宽光致发光。的p ...更多信息这些晶体的光致发光光谱被取代无序不均匀地加宽。这些晶体中Ce_（13）+Ce_（14）D_（13）+Ce_（14）D_（11）吸收带的最低峰能量与YAG激光的三次谐波（355 nm）相一致。生长了一种新的荧光粉Ce_（60）D_13 + Ce_（60）D_1掺杂的BaMgF_（60）D_24_（60）D_2晶体。Ce_（13）~（13）+Ce_（13）~（13）D_1在紫外区的不同光谱归因于晶体中Ce_（13）~（13）+Ce_（13）~（13）D_1位的规则性和微扰性。BaMgF晶体中Ce_（13）+Ce_（24）D_（24）和Ca_（24）D_（22）D_（24）D_Ce_xNd_xD 13 + Ce_xNd_xD 1晶体有望成为高增益、宽调谐范围的新型激光材料.在紫外和红外飞秒激光激发下，Ce掺杂黄长石晶体Ca YAl D22 Al 2 O3 D22 Al 2 O3 D27 Al 2 O3 D27 Al 2 O3 D22和CaYAl Al 2 O3 D23 Al 2 O3 D27 Al 2 O3 D27 Al 2 O3 D27 Al 2 O3 D22除了产生短寿命（40 ns）的本征Ce掺杂D13+ Al 2 O3 D1发光外，还产生长寿命的磷光。除去照射光后，磷光持续不少于1小时。长时间的磷光可以解释由一个模型的电子-空穴复合在Ce的电子-空穴D13+电子-空穴D1网站所造成的跳跃运动，这是由热激活过程中发生。这是首次观察到Ce_xD_1_3 + Ce_xD_1的长余辉发光。这种新的光学函数在自发消失的图像图案和限时三维光存储器件的制作中将是有用的。少