High efficiency all-optical polarization conversion of cw 1.55 μm lasers with liquid crystals by nonresonant optical wave mixing

Summary form only given. In this paper, we revisit the theory and practice of laser induced orientational scattering, in which a polarized ´pump´ laser is converted into its orthogonal polarization component by two-beam coupling effects between the ´pump´ and its scattered noise. We consider the case of an extraordinarily polarized laser incident on a planar nematic film with the optical electric field parallel to the director axis. We demonstrate the feasibility of an all-optical polarization conversion process using a cw 1.55 μm laser, to our knowledge for the first time. The liquid crystal used is pure E-7 (EM Chemicals), which has a nematic-isotropic phase transition temperature of 60.5°C. The laser used is an erbium doped fiber laser capable of 2 W unpolarized output.