Liquid-crystal-based fiber components that exploit the high birefringence and electrooptic effect of liquid crystals, are versatile. A single-mode fiber enclosed with planar-aligned liquid crystals is reported on in this paper. The fiber was etched nearly to its core. The output light was exercised through the evanescent field coupling between the fiber and surrounding liquid crystals. To achieve an effective access to the evanescent field, the etch depth was studied first. When the fiber was etched to 10-mu m diameter, obvious light leakage occurred. Once the electric field was switched on, the polarization selection and intensity modulation were examined. A theoretical description of the optical characteristics were also given.