Hole-assisted holey fiber and low bending loss multimode holey fiber

摘要

A high-performance HAHF that achieves both low bending loss L<Sub>B</Sub> and a short cut-off wavelength λ<Sub>C</Sub> is obtained. The fiber is a hole-assisted holey fiber including a core region; a cladding region around the core region, the core region having a higher refractive index than that of the cladding region; and a plurality of holes that are provided in the cladding region around the core region.
The core region (22) comprises a first core (24) at a center and a second core (25) around the first core (24) which are made of materials having two different respective indexes higher than that of a material of the cladding region.