An optical fiber coupling, for example, an optical switch, for coupling a
light source with a light-receiving end face of an optical waveguide
comprises a lens for focusing a light beam emitted from the light source
at a focal point on the light-receiving end face of the optical
waveguide. An adaptive coupler positioned in the optical path is
responsive to a beam steering control signal for steering and aligning
the focal point relative to the light-receiving end face of the optical
waveguide.