Temperature dispersion of refractive indices in β‐BaB2O4 and LiB3O5 crystals for nonlinear optical devices
Temperature dispersion of refractive indices in β‐BaB2O4 and LiB3O5 crystals for nonlinear optical devices
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DOI：
10.1063/1.360499
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发表时间：
1995-12
影响因子：
3.2
通讯作者：
G. Ghosh
中科院分区：
文献类型：
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作者：
G. Ghosh
热光系数，即折射率随温度的变化（dn/dT），决定了非线性光学激光器件的温度特性。缺乏适当的 dn/dT 数据阻碍了对硼酸钡和三硼酸锂晶体中各种参数三波相互作用的温度调节行为的评估。使用基于热膨胀系数、激子带隙温度系数和等熵带隙的物理模型对这些 dn/dT 值进行严格分析。根据热光系数和室温 Sellmeier 系数计算出的光学常数用于计算沿两种晶体主轴的任何工作温度和波长的折射率。评估温度敏感性并与实验值进行彻底比较。此外，这项研究解释了现有的非线性光学器件，特别是最近推出的飞秒旅行......
The thermo‐optic coefficients, i.e., the variation of refractive index with temperature (dn/dT), determine the temperature characteristics of nonlinear optical laser devices. A lack of proper dn/dT data prevents the assessment of the temperature‐tuning behavior of various parametric three‐wave interactions in barium borate and lithium triborate crystals. These dn/dT values are analyzed critically by use of a physical model based on the thermal expansion coefficient, the temperature coefficient of the excitonic band gap, and an isentropic band gap. The computed optical constants from the thermo‐optic coefficients and the room temperature Sellmeier coefficients are used to calculate the refractive indices for any operating temperature and wavelength along the principal axes of both crystals. Temperature sensitivities are evaluated and thoroughly compared to the experimental values. Also, this study interprets the existing nonlinear optical devices, in particular, the recently introduced femtosecond travelin...