An optical fiber is provided that includes a core region and a cladding region. The core region is formed of silica glass doped with chlorine and/or an alkali metal. The cladding region surrounds the core region and includes an inner cladding directly adjacent to the core region, an outer cladding surrounding the inner cladding, and a trench region disposed between the inner cladding and the outer cladding in a radial direction. The trench region has a volume of about 30% Δ-micron2 or greater. Additionally, the optical fiber has an effective area at 1550 nm of about 100 micron2 or less.