A novel microstructured optical fiber with high birefringence

Abstract

High birefringence optical fibers such as elliptical core fibers and many highly birefringent photonic crystal fibers usually broke the symmetry of circle by introduced C 2ν symmetry. In this paper, a novel microstructured high birefringence optical fiber with C 1ν symmetry is proposed. Four air holes were introduced into the core of a circular optical fiber, circular symmetry was broken, and the core of this kind of optical fibers only maintained C 1ν symmetry. The degeneracy fundamental mode LP 01 was split into two modes LP x 01 , LP y 01 because the symmetry of C 1v is lower than that of C 2ν , the difference between the patterns of the two modes field was larger. Using multipole method, we calculated the propagation constants of modes LP x 01 and LP y 01 , the modal birefringence B is to the magnitude of 10 -2 which is almost tenfold greater than that of many highly birefringence photonic crystal fibers. The other advantage of this kind of optical fibers is that the fabrication of fibers with a few air holes is easier than that of photonic crystal fibers with many air holes.