Dědič Václav, Sanitrák Jakub, Fridrišek Tomáš, Rejhon Martin, Morzhuk Bohdan, Shestopalov Mykhailo, Kunc Jan
Opt Express. 2023 Oct 9;31(21):34123-34142. doi: 10.1364/OE.502197.
In this paper, we introduce a method for mapping profiles of internal electric fields in birefringent crystals based on the electro-optic Pockels effect and measuring phase differences of low-intensity polarized light. In the case of the studied 6H-SiC crystal with graphene electrodes, the experiment is significantly affected by birefringence at zero bias voltage applied to the crystal and a strong thermo-optical effect. We dealt with these phenomena by adding a Soleil-Babinet compensator and using considerations based on measurements of crystal heating under laser illumination. The method can be generalized and adapted to any Pockels crystal that can withstand sufficiently high voltages. We demonstrate the significant formation of space charge in semi-insulating 6H-SiC under illumination by above-bandgap light.
在本文中，我们介绍了一种基于电光泡克耳斯效应绘制双折射晶体内部电场分布图并测量低强度偏振光相位差的方法。对于所研究的带有石墨烯电极的6H-SiC晶体，在施加于晶体的零偏置电压下，双折射和强烈的热光效应会对实验产生显著影响。我们通过添加一个索累-巴比涅补偿器，并基于激光照射下晶体加热的测量结果进行考量，来处理这些现象。该方法可以推广并适用于任何能够承受足够高电压的泡克耳斯晶体。我们证明了在高于带隙光的照射下，半绝缘6H-SiC中会显著形成空间电荷。
