Ultrahigh birefringent nonlinear microstructured fiber

In this letter, we present the fabrication of a microstructured fiber with high birefringence suitable for nonlinear applications. The fiber has been fabricated adapting the stack and draw method for microstructured fibers. The birefringence of the fiber is achieved inducing ellipticity to the air-hole array by controlling the lateral tension between preform and jacketing tube. Values of the group index birefringence higher than 7/spl times/10/sup -3/ are demonstrated.