Microstructured optical fiber and optical module

摘要

A microstructured optical fiber is structured with a core region (10) and a plurality of cladding regions (11-14) surrounding the core region. Chromatic dispersion is relatively flat over a broad wavelength range with a small effective area, without need for air holes that are unacceptably small. An enlarged effective core area is obtained by selectively closing the holes in the innermost cladding, which holes are smaller and easier to close than the holes in other regions. <IMAGE>