  Classical single-mode fiber interferometers, using one fiber per aperture,
have very limited imaging capabilities and small field of view. Observations of
extended sources (resolved by one aperture) cannot be fully corrected for
wavefront aberrations: accurate measurements of object visibilities are then
made very difficult from ground-based fiber interferometers. These limitations
are very severe for the new generation of interferometers, which make use of
large telescopes equipped with adaptive optics, but can be overcome by using
several fibers per aperture. This technique improves the wide field imaging
capabilities of both ground-based and space interferometers.
