Exemplary embodiments of the present invention provide for methods to
launch data signals from single mode fiber optic cable into legacy
multimode fiber optic cable. In one exemplary embodiment, a single mode
fiber is offset slightly from the axis of a multimode fiber, thus only
exciting the outer mode of the multimode fiber. In an alternate exemplary
embodiment, a core portion of the single mode fiber is exposed, heated,
and fused with a cladding portion of the multimode fiber. In yet another
alternate exemplary embodiment, various lenses can be used to collimate
and focus light signals from single mode fibers into multimode fibers,
and vice versa. In these exemplary embodiments, the transmitted light
signals can be in the range of from 1470 to about 1610 nm with, for
example, a 20 nm channel separation. Other wavelengths and channel
separations are also possible.