2-D layer structure of index in KDP crystal and creation of diffraction grating

KDP晶体折射率的二维层结构及衍射光栅的制作

• 批准号: 14350009
• 负责人: NAKATSUKA Masahiro
• 金额: $ 4.29万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350009/
• 关键词: Water-soluble crystal; Layered index structure; Impurity doping; Diffraction effect; Diffractive optical element; Laser damage threshold; KDP crystal; Automatic rapid growth method of crystal; KDP; 高速育成; 縞構造; 回折格子; 屈折率構造; 不純物添加結晶

The rapid growing method of water-soluble crystals has been developed. In order to keep a controllability of crystal growth, an automatic growing technology was established by measuring a super-saturation of the solution. The growth rate was increased from 1-2 mm/day in a conventional method to 50 mm/day in the rapid growth method.A selective inclusion of an ionic metal as an impurity in the crystal, such as iron ion, has been studied in the rapid growing method in which a growth rate has been controlled in time. As a result, KDP crystal has been found having a layered structure of index in an a-axis. But, a crystal structure of KDP shows needle-like one at a growth with a high impurity level in a solution.The two dimensional structure of index in a crystal has been achieved of several micron thickness. Optical parameters were investigated as a diffractive optic element. The theoretical properties of a transmission or reflective grating were summarized with a diffraction efficiency, wavelength matching, and allowance of the diffraction.The diffraction effect by layered structure of index was measured in an experiment showing a several-microns structure, then suggesting that 10^<-4>□ 10^<-5> index mismatching was needed for an efficient diffraction.The thermal shock parameter of KDP was measured for increasing strength of crystal at using an average power condition.In conclusion, the basic technology and knowledge have been established for a development of the diffractive optics in use at power laser system such as pulse compression, so on.

发展了水溶性晶体的快速生长方法。为了保证晶体生长的可控性，建立了一种通过测量溶液过饱和度来实现晶体生长自动化的技术。快速生长法的生长速度从传统方法的1-2 mm/天提高到50 mm/天。在快速生长法中，研究了作为杂质的离子金属（如铁离子）在晶体中的选择性包含，其中生长速度已被及时控制。结果，发现KDP晶体在a轴上具有折射率的层状结构。但在高杂质浓度的溶液中生长的KDP晶体结构呈针状，在几微米厚的晶体中获得了二维折射率结构。作为衍射光学元件的光学参数进行了研究。从衍射效率、波长匹配和衍射裕度三个方面总结了透射光栅和反射光栅的理论特性。通过实验测量了折射率分层结构的衍射效应，指出折射率分层结构的衍射效率需要达到10^ □ 10 ^的折射率失配。测量了KDP晶体的热冲击参数，以提高晶体的强度。实验结果表明<-4>，折射率分层结构的衍射效率比折射率分层结构的衍射效率高，而折射率分层结构的衍射效率比折射率分层结构的衍射效率高。实验结果表明，折射率分层结构的衍射效率比折射率分层结构的衍射效率高，而折射率分层结构的衍射效率比折射率分层结构的衍射效率<-5>高最后，为进一步发展衍射光学在脉冲压缩等大功率激光系统中的应用奠定了基础。

项目成果

M.Nakatsuka, H.Yoshida, Y.Fujimoto, K.Fujioka, H.Fujita: "Recent Topics in Engineering for Solid-state Peak-power Lasers in Repetitive Operation"Journal of Korean Physical Society. Vol.43, No.4. 723 (2003)

M.Nakatsuka、H.Yoshida、Y.Fujimoto、K.Fujioka、H.Fujita：“重复操作中固态峰值功率激光器工程的最新主题”韩国物理学会杂志。

M.Nakatsuka, H.Yoshida, Y.Fujimoto, K.Fujioka, H.Fujita: "Recent Topics in Engineering for Solid-state Peak-power Lasers in Repetitive Operation"Journal of Korean Physical Society. Vol.43,No.4. 723 (2003)

M.Nakatsuka、H.Yoshida、Y.Fujimoto、K.Fujioka、H.Fujita：“重复操作中固态峰值功率激光器工程的最新主题”韩国物理学会杂志。