Side chain liquid crystalline condensation polymers exhibiting nonlinear optical response

An optical light switch or light modulator device with a polymeric nonlinear optical component comprising a transparent solid medium of a thermotropic liquid crystalline polymer which is characterized by a recurring monomeric unit corresponding to the formula:

• ##STR23## where P is a polyester or polyamide condensation polymer main chain unit, S is a flexible spacer group having a linear chain length of between about 0-20 atoms, M is a pendant mesogen which exhibits a second order nonlinear optical susceptibility .beta. of at least about 5.times.10.sup.-30 esu as measured at 1.91 .mu.m excitation wavelength, and where the pendant mesogens comprise at least about 10 weight percent of the polymer, and the polymer has a glass transition temperature above about 40.degree. C.