| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress higher-order modes due to resonant coupling in bend-compensated optical fibers. <P>SOLUTION: A refractive index profile and a bending radius are configured so that there is selective resonant coupling of at least one HOM, but not a fundamental mode, in a bent segment of a fiber. In an embodiment, a core region is configured to guide propagation of signal light in a fundamental traverse mode and at least one higher-order traverse mode. A cladding region includes an outer cladding region and an annular trench region. The trench region includes at least one axially extending, raised-refractive index pedestal region having a refractive index higher than the outer cladding region. Within the bent segment, at least one pedestal region is configured (i) to support the propagation of at least one traverse mode and (ii) to resonantly couple at least one of the higher-order traverse modes (HOMs) of the core region to at least one traverse mode of the pedestal region when the fiber is bent to the radius within a predetermined range of radii. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
