
operate in the regime where SMF is multimoded. Although the fundamental modes
in both SM F and PCF have similar dispersion profiles, the presence of higher order
modes (not guided in the PCF, which is ESM) makes the use of SMF impractical.
A further degree of freedom in GVD design may be gained by working with
multicomponent glasses, such as Schott SF6 (Figure 14.2(e)), where the intrinsic
zero dispersion point occurs at 1.8 mm [7]. In highly nonlinear small-core PCF,
this shifts the whole dispersion landscape to longer wavelengths than in a silica-
based PCF with the same core size and geometry.
Hollow Core
Hollow-core fiber behaves in many respects ...