Highly birefringent V-groove liquid core fiber

We report a new efficient light guidance along a liquid core using an open V-groove. Guiding properties were analyzed using finite element method in terms of the single mode guidance condition, and the corresponding modal birefringence. We experimentally demonstrated a silica V-groove fiber with an opening angle of 40°, which was spliced to single mode fibers at both ends. A liquid with the refractive index of 1.455 was filled to serve as a core along a maximum length of 47cm. We confirmed the single mode guidance and birefringence consistent to theory, which will enable polarimetric liquid sensing.