Novel bend-resistant design of single-mode microstructured fibers

The authors designed and manufactured two types of a silica-based microstructured fiber (also referred to as holey fiber) having a large core size: first type which contains a circular core and correspondingly possesses the circular symmetry in the waveguide cladding, and second one representing non-typical triangular structure with periodically placed large and small holes. The primary aim of investigation remained the same as at the previous stages, i.e. to create favourable conditions for the strong attenuation of the higher-order mode. The main technological method we applied was variation of air content in the area surrounding the core, especially in the first air-hole ring.