Single-design-parameter microstructured optical fiber for chromatic dispersion tailoring and evanescent field enhancement

A microstructured optical fiber with a single design parameter is proposed and demonstrated. In such a structure three thin, long glass webs join in the fiber center, forming its core. By changing the web thickness it is possible to tune the zero-dispersion wavelength from $\sim 0.7\text{to}>2.0\mu \mathrm{m}$ while keeping a tiny core area and single-mode guidance. Supercontinuum generation is shown in a silica fiber with a web thickness of $850\mathrm{nm}$. The small core area and the massive hole area also make the structure very attractive for the sensing and study of fluids.