四价掺杂铌酸锂晶体的极化特性研究.docVIP

 n 四价掺杂铌酸锂晶体的极化特性研究# 朱美玲，何为毅，张荣，刘宏德** （南开大学物理科学学院，教育部弱光非线性光子学重点实验室，天津 300071） 5 10 15 20 25 30 35 40 摘要：本文主要研究了四价掺杂（锆、铪）铌酸锂晶体的极化反转特性。研究发现掺锆铌酸 锂晶体的极化反转电场与其掺杂年度线性相关，掺入超过掺杂浓度阈值量的掺锆铌酸锂晶体 的最小反转电场为 7.25 kV/mm；而近化学计量比掺锆铌酸锂晶体可降低到 1 kV/mm 左右， 是同成分掺镁铌酸锂晶体的 20%。同时，利用光学方法观察了晶体反转过程，发现相比于掺 镁铌酸锂晶体，四价掺杂铌酸锂晶体的畴壁运动速度缓慢，畴壁的曲率半径更小，更易于制 备小尺寸畴结构。因此，综合其抗光损伤性能，四价掺杂铌酸锂晶体有望成为优良的全波段 型准相位匹配材料。 关键词：铌酸锂；掺锆；掺铪；极化反转 中图分类号：O735 Study on the polarization in the tetravalent doped lithium niobate crystals Zhu Meiling, He Weiyi, Zhangrong, Liu Hongde (MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, TianJin 300071) Abstract: This paper studies the tetravalent-doped (Zr, Hf) lithium niobate crystals polarization reversal characteristics. Study found that the switching field of the zirconium-doped lithium niobate crystals is linear with the dopment, the minimum of the swiching field of zirconium-doped lithium niobate with concentration exceeds the threshold amount is 7.25 kV/mm; and near-stoichiometric lithium niobate crystals doped zirconium is reduced to 1 kV / mm or so, which is 20% of the same composition Mg-doped lithium niobate crystals. Meanwhile, the crystal was observed using optical methods reverse the process, found that compared to Mg-doped lithium niobate crystal, tetravalent doped lithium niobate crystals has slow domain wall motion, domain wall radius of curvature smaller, easier to prepare small size domain structure. Therefore, theintegrated performance of its resistance to light damage, tetravalent doped lithium niobate crystal is expected to become an excellent full-band-type quasi-phase-matched materials. Keywords: lithium niobate; zirconium-doped; hafnium-doped; polarization reversal 0 引言 铌酸锂晶体是一种集电光、声光、压电、光弹、非线性、光折变及激光活性等效应于一 身的人工晶体，且具有自身机械性能稳定、易加工、耐高温、抗腐蚀、原材料来源丰富、价 格低廉、易生长成大晶体等优点，尤其是对很多杂质都具有良好的固溶性，且晶体的性能随 着掺杂的种类和数量的不同而发生明显的改变，是至今人们所发现的光学性能最多、综合指 标最好的晶体，具有十分广阔的市场应用前景，被称为“非线性光学硅”(silicon of nonlinear optics)[1]。 最近，Kokanyan 等人发现掺四价元素铪，