AC Field Modulation of Stimulated Orientational Scattering (SOS) Effect in nonlinear liquid crystal (NLC)

(Rosa) Xiao-Shan Tao

Mentor: Professor I.C. Khoo

 

             Laser induced dynamic grating and optical wave mixings in nonlinear optical media have been studied under various contexts. SOS is a research about the nonlinear coupling between optical waves and the NLC director axis. It consists of polarization and energy conversion process and has many potential applications in electro-optics. For example, its broadband polarization conversion characteristic allows the energy to transfer from one polarization to the other independent of input wavelength. Furthermore, it is also a good object for chaotic analysis because of the abundant dynamic behaviors of NLC materials under intense optical waves.

             Professor Khoo and his graduate students have successfully shown the detailed theoretical analysis for steady state SOS effect and realized the SOS effect in communication bandwidth. They also evaluated the influence of the material parameters of the SOS effect such as the viscosity coefficient and the elastic constant.

            SOS effect in NLC films is an interesting nonlinear optical response. Our goal is to see whether and how the AC modulating field affects the interaction between NLC director and the SOS signal. We expect to see the enhancement of the SOS effect due to the resonance of AC field and the reorientational grating of the NLC director.