- Abstract. A polarization independent Fabry–Perot liquid crystal tunable filter coupled to an optical fiber is demonstrated using polarization diversity. Using a Wollaston prism, the beam splits into two orthogonal beams, while the polarization of one of the beams is rotated by 90 deg using a variable half wave plate. The two beams are then combined into an optical fiber. Tuning of unpolarized light over the range 720 to 800 nm is demonstrated.