Effect of an external E-field on Non-Linear isotropic material.

hi,
Please help me to understand.
Can a non-linear isotropic material convert into a non linear anisotropic material by applying an external E-field in a particular direction?

Since, material is a non linear it's refractive index will be a function of E-field. If we apply an E-field in particular direction then refractive index may be change in that particular direction only because of isotropic, then the cause of an applying E-field will effect in conversion of isotropic material into anisotropic material. After removing the E-field, material will come back to it's previous condition.

Thank you

Can you think of a polarizer material such as LCD materials?