@article{oai:kitami-it.repo.nii.ac.jp:00007259,
 author = {Eguchi, Masashi and Tsuji, Yasuhide},
 issue = {4},
 journal = {Journal of the Optical Society of America B},
 month = {Apr},
 note = {Geometrical birefringence in circular- and elliptical-hole square-lattice holey optical fibers having a core consisting of a multiple defect is investigated. The effect of unidirectional extension of the core area on the birefringence of these holey fibers (HFs) is discussed. We demonstrate that, as expected, a high birefringence can be induced in circular-hole HFs by unidirectional extension of the core area. In contrast, the maximum birefringence of elliptical-hole HFs, the holes of which have their major axes parallel to the long axis of the core, is achieved in a core structure that has a single defect. We also found that for elliptical holes having their major axes orthogonal to the long axis of the core, an exchange of the fast and slow modes occurs between the two orthogonally polarized fundamental modes by birefringence compensation., (c) 2007 Optical Society of America, application/pdf},
 pages = {750--755},
 title = {Geometrical birefringence in square-lattice holey fibers having a core consisting of a multiple defect},
 volume = {24},
 year = {2007}
}