抄録
Non-degenerated higher-order coupled-mode fields of symmetrical four-core optical fibers are analyzed by using group-theory adapted point-matching method. In the ``non-degenerated higher-order coupled-modes'' treated in this work, each core field is composed with one of the fields of the LP11-mode group. Moreover, their propagation constants are distinct from those of other modes. The frequency-dependent electromagnetic fields of these modes are analyzed to clarify the field transition properties.