A Novel Microstructured Optical fiber with High Birefringence

摘要

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_(2v) symmetry. In this paper, a novel microstructured high birefringence optical fiber with C_(1v) 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_(1v) symmetry. The degeneracy fundamental mode LP_(01) was split into two modes LP_(01)~x, LP_(01)~y because the symmetry of C_(1v) is lower than that of C_(2v), the difference between the patterns of the two modes field was larger. Using multipole method, we calculated the propagation constants of modes LP_(01)~x and LP_(01)~y, 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.