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Ultra-fast optical logic devices

Assignee: Nokia Bell Labs
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Filing: 1989-09-25
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Granted: 1990-06-12
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Expires: 2009-09-25
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Abstract

Abstract Combinatorial (Boolean) logic functions are provided by ultrafast optical logic devices which utilize soliton trapping between two optical signals propagating in a birefringent fiber. The logic devices are three terminal devices having orthogonally polarized soliton input signals and a single output signal. Optically filtering the output from the fiber permits the desired combinatorial logic operation to be performed on the input optical signals. Logic operations include AND, exclusive-OR, NOT, and NOR functions. In operation, the devices exhibit phase insensitivity, low switching energy, high contrast ratio between output logic levels, and cascadability. In one embodiment of the invention, a first optical signal and a second optical signal are optically coupled into the principal axes of a birefringent fiber. A Fabry Perot etalon centered at the center frequency of both the first and second signals is utilized to realize a exclusive-OR operation whereas centering the etalon on the frequency related to the spectral shift caused by soliton trapping realizes an AND operation.

Inventors

  • 👤 Mohammed N. Islam

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 10:42
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/3515; G02F1/3517

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 104 words
An optical logic device for performing Boolean logic operations on first and second optical signals, said optical logic device comprising: dielectric waveguide means responsive to said first and second optical signals for causing soliton trapping to occur between individual pulses of said first and second optical signals, said first optical signal polarized substantially orthogonal to said second optical signal; means for coupling optically said first and second optical signals to an input end of said dielectric waveguide means and; means coupled optically to an output end of said dielectric waveguide means for filtering a predetermined spectral region of said first and second optical signals.
Claim 2
Dependent Claim 104 words
An optical logic device for performing Boolean logic operations on first and second optical signals, said optical logic device comprising: dielectric waveguide means responsive to said first and second optical signals for causing soliton trapping to occur between individual pulses of said first and second optical signals, said first optical signal polarized substantially orthogonal to said second optical signal; means for coupling optically said first and second optical signals to an input end of said dielectric waveguide means and; means coupled optically to an output end of said dielectric waveguide means for filtering a predetermined spectral region of said first and second optical signals.
Claim 3
Dependent Claim 29 words
The optical logic device as defined in claim 1 wherein said means for coupling includes means for polarizing said second optical signal substantially orthogonal to said first optical signal.
Claim 4
Dependent Claim 18 words
The optical logic device as defined in claim 2 wherein said means for filtering includes an Fabry-Perot etalon.
Claim 5
Dependent Claim 18 words
The optical logic device as defined in claim 3 wherein said dielectric waveguide means includes an optical fiber.
Claim 6
Dependent Claim 36 words
The optical logic device as defined in claim 4 wherein said predetermined spectral region is centered at the wavelength of said first and second optical signals, such that said Boolean logic operation is a Exclusive-OR function.
Claim 7
Dependent Claim 43 words
The optical logic device as defined in claim 4 wherein said predetermined spectral region is centered at the spectral shift wavelength due to said soliton trapping of said first and second optical signals, such that said Boolean logic operation is an AND function.
Claim 8
Dependent Claim 72 words
The optical logic device as defined in claim 3 further comprising means coupled optically to said output end for transmitting a predetermined polarization state of said first and second optical signals, said predetermined polarization state being substantially the same as that of said second optical signal and said predetermined spectral region centered on the wavelength of said first and second optical signals, such that said Boolean logic operation is an AND function.
Claim 9
Dependent Claim 32 words
The optical logic device as defined in claim 7 wherein said dielectric waveguide means includes first and second separate optical paths for supporting optical signal propagation on each of said optical paths.
Claim 10
Dependent Claim 53 words
The optical logic device as defined in claim 8 further comprising means for coupling said first optical signal to said first optical path, means for coupling said second optical signal to each of said first and second optical paths, and means for combining said first and second optical paths into an output signal.
Claim 11
Dependent Claim 30 words
The optical logic device as defined in claim 9 wherein said dielectric waveguide means includes first and second optical fibers corresponding to said first and second separate optical paths, respectively.
Claim 12
Dependent Claim 32 words
The optical logic device as defined in claim 9 wherein said dielectric waveguide means includes an optical fiber, said first and second optical paths corresponding to counterpropagating directions within said optical fiber.
Claim 13
Dependent Claim 180 words
An optical logic device for performing a NOR Boolean logic operation on a first and second optical signals, said optical logic device comprising: dielectric waveguide means responsive to said first and second optical signals, and a third optical signal, for causing soliton trapping to occur between individual pulses of said first and third optical signals, and said second and third optical signals in the absence of said first optical signal, said third optical signal polarized substantially orthogonal to said first and second optical signals; means for coupling optically said first, second and third optical signals to an input end of said dielectric waveguide; means coupled optically to an output end of said dielectric waveguide means for filtering a predetermined spectral region of said first, second and third optical signals, said predetermined spectral region centered on the wavelength of said first and second optical signals; and means coupled optically to said output end for transmitting a predetermined polarization state of said first and second optical signals, said predetermined polarization state being substantially the same as that of said third optical signal.
Claim 14
Dependent Claim 180 words
An optical logic device for performing a NOR Boolean logic operation on a first and second optical signals, said optical logic device comprising: dielectric waveguide means responsive to said first and second optical signals, and a third optical signal, for causing soliton trapping to occur between individual pulses of said first and third optical signals, and said second and third optical signals in the absence of said first optical signal, said third optical signal polarized substantially orthogonal to said first and second optical signals; means for coupling optically said first, second and third optical signals to an input end of said dielectric waveguide; means coupled optically to an output end of said dielectric waveguide means for filtering a predetermined spectral region of said first, second and third optical signals, said predetermined spectral region centered on the wavelength of said first and second optical signals; and means coupled optically to said output end for transmitting a predetermined polarization state of said first and second optical signals, said predetermined polarization state being substantially the same as that of said third optical signal.
Claim 15
Dependent Claim 31 words
The optical logic device as defined in claim 12 wherein said means for coupling includes means for polarizing said third optical signal substantially orthogonal to said first and second optical signals.
Claim 16
Dependent Claim 18 words
The optical logic device as defined in claim 13 wherein said means for filtering includes a Fabry-Perot etalon.
Claim 17
Dependent Claim 18 words
The optical logic device as defined in claim 14 wherein said dielectric waveguide means includes an optical fiber.
Claim 18
Dependent Claim 151 words
An optical logic device for performing a NOT Boolean logic operation on a first optical signal, said optical logic device comprising: dielectric waveguide means responsive to said first and second optical signals for causing soliton trapping to occur between individual pulses of said first and second optical signals, said first optical signal polarized substantially orthogonal to said second optical signal; means for coupling optically said first and second optical signals to said dielectrical waveguide means; means coupled optically to an output end of said dielectric waveguide means for filtering a predetermined spectral region of said first and second optical signals, said predetermined spectral region centered on the wavelength of said first and second optical signals; and means coupled optically to said output end for transmitting a predetermined polarization state of said first and second optical signals, said predetermined polarization state being substantially the same as that of said second optical signal.
Claim 19
Dependent Claim 151 words
An optical logic device for performing a NOT Boolean logic operation on a first optical signal, said optical logic device comprising: dielectric waveguide means responsive to said first and second optical signals for causing soliton trapping to occur between individual pulses of said first and second optical signals, said first optical signal polarized substantially orthogonal to said second optical signal; means for coupling optically said first and second optical signals to said dielectrical waveguide means; means coupled optically to an output end of said dielectric waveguide means for filtering a predetermined spectral region of said first and second optical signals, said predetermined spectral region centered on the wavelength of said first and second optical signals; and means coupled optically to said output end for transmitting a predetermined polarization state of said first and second optical signals, said predetermined polarization state being substantially the same as that of said second optical signal.
Claim 20
Dependent Claim 29 words
The optical logic device as defined in claim 16 wherein said means for coupling includes means for polarizing said control optical signal substantially orthogonal to said first optical signal.
Claim 21
Dependent Claim 18 words
The optical logic device as defined in claim 17 wherein said means for filtering includes a Fabry-Perot etalon.
Claim 22
Dependent Claim 18 words
The optical logic device as defined in claim 18 wherein said dielectric waveguide means includes an optical fiber.

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