We investigate dual concentric core and microstructure fiber geometries for dispersion compensation. Dispersion values as large as - 59 000 ps/(nm km) are achieved, over a broad wavelength range with full width at half maximum exceeding 100 nm. The trade-off between large dispersion and mode area is studied. Geometries with an effective mode area of 30 mum(2) and dispersion - 19 000 ps/( nm km) and 80 mum(2) with - 1600 ps/(nm km) are proposed. (C) 2005 Optical Society of America.