MAXWELL STRESS INDUCED FLOW-DEFORMATION AND OPTICAL NONLINEARITIES IN LIQUID CRYSTALS (Invited Paper)

Abstract

Abstract-We present a critical account of intense pulsed-laser field induced refractive index changes caused by flow, crystalline axis reorientation and distortion and other high order photonic processes in transparent liquid crystals. In particular, the optical nonlinearity associated with Maxwell Stress induced flow-reorientation in nematic liquid crystals is explicitly calculated, and their possibility for all-optical switching application is experimentally demonstrated. Similar flows processes have also been observed in Blue-Phase liquid crystals with nanosecond and picosecond pulsed-lasers.

Origin of optical nonlinearity of photo-responsive liquid crystals revealed by transient grating imaging

“…The detailed expressions can be found in the original paper 26 , and it is noted here the LC flows are directly coupled to pump laser via the field-induced stress . This field-induced stress is sometimes called Maxwell stress 27 , where the polarized charge is a function of material dielectric property and external fields. The LC director, , advances in time by the torque generated by the strain tensor and the vorticity tensor under a shear flow.…”