Grin rod lens optical backplane bus

Abstract

GRID rod lenses extend between the faces of beam-splitting prisms that are in the transmitting and receiving light beam paths of an optical backpanel bus. The GRIN rod lenses are secured in segments to the inner opposing faces of pairs of beam-splitting prisms along the light beam paths with optical grade epoxy in order to reduce undesirable reflections when vibrations occur. These GRIN rod lenses are contained in a Kovar channel which has a pair or elongated V-shaped grooves. Kovar is the preferred material because it has approximately the same index of expansion as the GRIN rod lenses. The GRIN rod lenses of the transmitting path are secured in one V-shaped groove while the GRIN rod lenses of the receiving path are secured in another V-shaped groove. GRIN rod lenses that run normal to the transmitting and receiving light paths are also secured with optical grade epoxy to the beam-splitting prisms and are coupled to optical transmitters and receivers through optical fibers to complete the light path from any transmitter on the bus to any receiver. A plurality of smaller diameter GRIN rod lens can be coupled to the larger diameter transmitter and receiver coupling GRIN rod lens that run normal to the transmitting and receiving path so that a number of optical fibers may be coupled to each normally disposed GRIN rod lenses. This allows the same transmitting and receiving paths to be shared by a number of light signals.