We developed a polyimide optical waveguide with multi-fan-out which ca
n be used as an optical interconnection between the many LSI chips in
a multichip module system. The propagation direction of the signal lig
ht is changed from horizontal to vertical and from;vertical to horizon
tal using aluminum micromirrors in this waveguide. We then introduced
a signal light into this waveguide, the propagation direction of which
was bent by an aluminum micromirror. It impinged on the photodiode to
induce a significant increase in the photodiode current.