Stimulated Orientational Scattering in Liquid Crystals

In liquid crystals, laser induced director axis reorientations lead to the possibility of another type of stimulated scattering process,in which the spontaneous noise 

Consider, for example, the case of an extraordinarily polarized laser incident on a planar nematic film with the optical electric field Ee = parallel to the 

This grating will mediate stimulated scattering between the ordinary and extraordinary wave components. In analogy to stimulated Brillouin scattering, the growth of the scattered wave component is dependent on the intensity of the incident laser, and 

To analyze the process quantitatively, the starting point is the Euler-Lagrange equation for the free energy /of the system of NLC film under an applied field  

Taking 6(z,0 as the independent variable, the equation governing the reorientation angle 6(z,0 becomes 

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