太赫兹场致液晶双折射效应的研究

Birefringence effect of liquid crystals induced by terahertz field

液晶材料是信息显示设备中的重要组成部分,其在外场作用下所表现的高双折射特性是其被用于显示的关键条件。利用强太赫兹波作为外场,激发液晶5CB材料的双折射效应。结合太赫兹时域光谱系统通过测量不同偏振的太赫兹波的透过率,研究了太赫兹场致液晶在太赫兹波段的双折射效应。分析了液晶的双折射效应与外场强的变化关系、频率响应特性等方面。研究结果表明在强场太赫兹波激发下,液晶的双折射现象随场强的增大而增大,双折射值与外部场强平方成正比,且液晶5CB对于太赫兹激发的双折射效应存在一定的阈值。

Liquid crystal materials are an important component of display devices,and their high birefringence under the action of external fields is a crucial condition for their use in display.Using a strong terahertz wave as an external field to excite the birefringence effect of liquid crystal 5CB material,the birefringence effect of terahertz field induced liquid crystal in the terahertz band was studied.With a terahertz time domain spectroscopy system,we measured the transmittance of terahertz waves with different polarization states.The relationship between the birefringence effect of liquid crystals and the external field strength,as well as the frequency response characteristics,were analyzed.The results show that the birefringence of liquid crystal increases with the increase of field strength provided by strong terahertz waves,and the birefringence value is proportional to the square of field strength,and there is a threshold value for the birefringence effect of liquid crystal 5CB excited by terahertz waves.