高性能硼酸盐磁光材料探索与晶体生长

Magneto-optic (MO) materials has the unique property of nonreciprocal transmission of light in a magnetic field. When combined with the polarizers, it only allows light to pass in one direction, thus acting as an isolator, which has vital important applications in optic communication and high power laser systems. At present, the commercial MO crystal, Tb3Ga5O12-TGG, shows relative high absorption and large insert loss especially in the visible and near infrared ranges. Therefore, MO crystals with low absorption loss and high MO effect are urgently needed. As it is well known during the development of borate nonlinear optical crystal, a field with great success in our country, that the borate crystals possess the characteristic of high transparency and low absorption. Following this route, we expect to find new high figure of merit(FOM) MO materials in the borate systems. In this proposal, we will focus on the absorption mechanisms, relationship of local symmetry to the Verdet coefficients, improving the crystal growth processes, and finally will obtain new borate MO crystals with better FOM over commercial crystals based on our previous findings of potential MO borates: LiCaTb5(BO3)5 and LiSrTb2(BO3)3.

磁光材料是利用光学材料在磁场下对光的偏振方向进行非可逆单向旋转的特性的一类晶体材料，它与偏振器件连用可实现激光的单向通过，实现光隔离器等用途，在光通信及大功率激光输出中具不可替代作用。目前在可见、近红外及高功率激光应用中商用Tb3Ga5O12-TGG晶体吸收较高、插入损耗大，急需吸收低磁光系数大的新型磁光材料。总所周知、硼酸盐晶体具有高透过低吸收等特点，我国在硼酸盐非线性光学晶体研究中取得巨大成功。我们将延续这一优势，期望在硼酸盐晶体中探索出高性能磁光晶体材料。本申请将研究稀土硼酸盐吸收机制，微观对称性与晶体Verdet系数关系，在前期已发现两种具潜在高优质因子的硼酸盐LiCaTb5(BO3)5和LiSrTb2(BO3)3晶体的基础上，改进稀土硼酸盐生长技术，获得磁光效应优于商用晶体的新型硼酸盐磁光晶体材料。

磁光材料是利用光学材料在磁场下对光的偏振方向进行非可逆单向旋转的特性的一类晶体材料，它与偏振器件连用可实现激光的单向通过，实现光隔离器等用途，在光通信及大功率激光输出中具不可替代作用。目前在可见、近红外及高功率激光应用中商用Tb3Ga5O12-TGG晶体吸收较高、插入损耗大，急需吸收低磁光系数大的新型磁光材料。总所周知、硼酸盐晶体具有高透过低吸收等特点，我国在硼酸盐非线性光学晶体研究中取得巨大成功。通过研究稀土硼酸盐吸收机制，微观对称性与晶体磁性及Verdet系数关系，改进稀土硼酸盐生长技术，获得了磁光效应优于商用晶体的新型LCTB硼酸盐磁光晶体材料。在项目执行期间我们按还获得了多种新型相关化合物，对其结构、磁光、光学性质、磁性、非线性效应等进行了理论和实验研究，发现了新的具潜在应用价值的新型磁光晶体，圆满完成了计划目标。