A hole-assisted fiber comprises a core region and a cladding region, where the cladding region includes multiple substantially elliptical holes spaced apart from each other to surround the core region. The holes are filled with one of a gas and a liquid to form a low refractive index portion of the cladding region. In addition, a method of fabricating a hole assisted fiber includes forming one or more slots in the perimeter of the cladding region. A tube is overcollapsed around the perimeter of the cladding region to form one or more channels, where the one or more channels bounded on one side by the overcollapsed tube. A fiber is drawn from the overcollapsed preform. An internal pressure is applied to the one or more channels during the fiber drawing step to form one or more holes of a pre-selected shape within the cladding region.
