Bidirectional free-space optical bus for electronics systems

Claim 2

A subsystem for an electronics system having multiple subsystems mounted in a frame so as to define a single axis passing through said subsystems, said one subsystem comprising: a support adapted for mounting on said frame; function circuits carried by said support, and adapted to produce a first electrical signal and to receive a second electrical signal; optical generating means for converting said first electrical signal into a first optical beam having a predetermined polarization; an amplitude beam splitter mounted on said support so as to intersect said axis, and optically coupled to said generator for transmitting said first optical beam in two opposite directions along said axis in said predetermined polarization, and for receiving a second optical beam having said predetermined polarization from either of said two opposite directions along said same axis; optical detecting means coupled to said amplitude beam splitter for converting said second optical beam into said second electrical signal.

Claim 3

The subsystem of claim 1 wherein said support and said frame include means for cooperatively holding said amplitude beam splitter in a predetermined position with respect to said axis.

Claim 4

The subsystem of claim 2 wherein said holding means includes connector means for providing electrical connections between said frame and said subsystem.

Claim 5

The subsystem of claim 2 wherein said holding means includes guide means.

Claim 6

The subsystem of claim 1 wherein said support includes at least one aperture along said axis for passing said optical beam through said support.

Claim 7

The subsystem of claim 1 wherein said support comprises a card having mounted thereon said function circuits, said optical generator, said amplitude beam splitter, and said optical detector

Claim 8

The subsystem of claim 1 wherein said first electrical signal is a single serial signal.

Claim 9

The subsystem of claim 7 wherein said function circuits include means for converting multiple parallel electrical signals into said single serial first signal.

Claim 10

The subsystem of claim 1 wherein said second electrical signal is a single serial signal.

Claim 11

The subsystem of claim 9 wherein said function circuits include means for converting said single serial second signal into multiple parallel electrical signals.

Claim 12

An optical interface unit for coupling electrical signals to an optical bus, comprising: optical generator for converting a first electrical signal into an outgoing beam having a first linear polarization mode; a polarizing beam splitter for passing said first outgoing beam and for deflecting an incoming optical beam having a linear polarization in a different mode from that of said outgoing beam; a polarization converter intercepting said first outgoing beam so as to convert its linear polarization to circular polarization, and further intercepting said second incoming beam so as to convert its circular polarization to linear polarization in said different mode; an amplitude beam splitter positioned so as to intercept said outgoing circularly polarized beam for transmitting said beam in two opposite directions along a single optical axis, and for receiving said incoming beam from both of said two opposite directions along said same axis and passing said incoming beam both along said axis in the other of said directions and to said polarization converter; an optical detector positioned so as to receive said incoming deflected beam from said polarizing beam splitter, for converting said incoming optical beam into said second electrical signal.

Claim 13

An optical interface unit for coupling electrical signals to an optical bus, comprising: optical generator for converting a first electrical signal into an outgoing beam having a first linear polarization mode; a polarizing beam splitter for passing said first outgoing beam and for deflecting an incoming optical beam having a linear polarization in a different mode from that of said outgoing beam; a polarization converter intercepting said first outgoing beam so as to convert its linear polarization to circular polarization, and further intercepting said second incoming beam so as to convert its circular polarization to linear polarization in said different mode; an amplitude beam splitter positioned so as to intercept said outgoing circularly polarized beam for transmitting said beam in two opposite directions along a single optical axis, and for receiving said incoming beam from both of said two opposite directions along said same axis and passing said incoming beam both along said axis in the other of said directions and to said polarization converter; an optical detector positioned so as to receive said incoming deflected beam from said polarizing beam splitter, for converting said incoming optical beam into said second electrical signal.

Claim 14

The unit of claim 11 wherein said amplitude beam splitter has a partially reflective internal surface positioned at an angle to said axis.

Claim 15

The unit of claim 12 wherein said amplitude beam splitter includes a reflection means positioned for intercepting a beam reflected from said partially reflecting surface and reflecting it back to said partially reflective surface.

Claim 16

The unit of claim 13 wherein said reflection means is a totally reflecting surface.

Claim 17

The unit of claim 13 wherein said reflection means is an external surface of said amplitude beam splitter.

Claim 18

The unit of claim 11 wherein said optical generator includes a semiconductor laser diode

Claim 19

The unit of claim 11 wherein said laser diode produces said first linear polarization mode.

Claim 20

The unit of claim 11 wherein said optical generator includes means for collimating said outgoing beam.

Claim 23

The method of claim 19 wherein said first and second linear modes are orthogonal to each other.

Claim 24

The method of claim 19 wherein the step of splitting said outgoing beam includes: reflecting a portion of said outgoing beam onto one direction of said linear axis; reflecting the remainder of said outgoing beam in a direction opposite its incidence; partially reflecting said totally reflected remainder onto the other direction of said linear axis.

Claim 25

The method of claim 19 wherein the step of splitting said incoming beam includes: partially reflecting said incoming beam along away from said linear axis; totally reflecting said partially reflected incoming beam to form said deflected incoming beam.