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

我们已经种植了CEI D13+ D1掺杂的氟化物[BAMGFIL D24 D2，CANAYFIL D26 D2]和氧化物[Melilite-Type Crystals AI D22 D22 D2B D23 D23 D23 D2O D27 D2（A = CA，Y; Y; Y; B = Al，SI]，这些是候选lastable Lasere and the uv uv uv uv uv uv uv uv and uv uv and uv uv and uv uv。为了在紫外线和可见区域中广泛扩散磷光体，我们研究了这些晶体的光学表征以及相关阴离子坐标多面角性晶体场的强度和低对称性的影响。这项研究的结果总结如下1。 II D12 D1D激发状态能级的最低能量和重心可以通过肾上腺素效应来解释，降低了由氟化物和氧化物晶体中CEI D13+ D1的Annion坐标polyhedra引起的对称性的降低。在CEII D13+IE D1掺杂的Melilite CAI D22IE D22IE D22SIOI D27IE D2和CAYALIE D23IE D2OI D27IE D27中，观察到近紫外线和紫罗兰区域的广泛光致发光。 P…这些晶体的更热发光光谱被替代障碍不均匀地扩大。这些晶体中CEII D13+IE D1抽象带的最低峰能与YAG激光器的第三个谐波（355nm）一致。种植了一种新的磷光CEI D13+IE D1掺杂的BAMGFILE D24IE D2晶体。 UV区域中CEI D13+IE D1的不同光谱分配是由于晶体中的常规和扰动的CEI D13+IE D1位点。 BAMGfile D24IE D2晶体中CEI D13+IE D1最低的5D激发态的能级与A nd Laser的第四个谐波（266nm）一致。成为新的激光材料，在紫外线和紫外线附近之间具有很高的增益和广泛的调谐范围3。 CEI D13+ E D1掺杂的Melilite晶体CAII D22 AL-D22 SIO-D27 D2和CAYAL-D23 D2O-D27 D2的UV兴奋或红外激光激光兴奋，以及持久的磷光，除了固有的CEI D13+ D1 ulipeiment（40）（40岁）。去除辐照光后，磷光持续不少于1小时。持久的磷光可以通过跳跃运动引起的CEI D13+ D1位点的电子孔重组模型来解释，这是由热激活过程发生的。这是CEI D13+IE D1的持续磷光的首次观察。这种新的光学功能将有助于制造不含赞助商的消失图像模式和时间限制的三维光学记忆设备。较少的