Ferroelectric crystals with giant electro-optic property enabling ultracompact Q-switches
Xin Liu, Peng Tan, Xue Ma, Danyang Wang, Xinyu Jin, Yao Liu, Bin Xu, Liao Qiao, Chaorui Qiu, Bo Wang, Weigang Zhao, Chaojie Wei, Kexin Song, Haisheng Guo, Xudong Li, Sean Li, Xiaoyong Wei, Long‐Qing Chen, Zhuo Xu, Fei Li, Hao Tian, Shujun Zhang
Abstract
Relaxor-lead titanate (PbTiO 3 ) crystals, which exhibit extremely high piezoelectricity, are believed to possess high electro-optic (EO) coefficients. However, the optical transparency of relaxor-PbTiO 3 crystals is severely reduced as a result of light scattering and reflection by domain walls, limiting electro-optic applications. Through synergistic design of a ferroelectric phase, crystal orientation, and poling technique, we successfully removed all light-scattering domain walls and achieved an extremely high transmittance of 99.6% in antireflection film–coated crystals, with an ultrahigh EO coefficient r 33 of 900 picometers per volt (pm V −1 ), >30 times as high as that of conventionally used EO crystals. Using these crystals, we fabricated ultracompact EO Q-switches that require very low driving voltages, with superior performance to that of commercial Q-switches. Development of these materials is important for the portability and low driving voltage of EO devices.