Optical double sideband modulation technique with increased spectral efficiency
First Claim
Patent Images
1. A device, comprising:
- a Mach-Zehnder interferometer modulator comprising an input port to receive an optical carrier beam at an optical carrier frequency and operable to modulate the optical carrier beam in response to a plurality of modulating signals at different modulating frequencies to produce a modulated optical beam carrying a plurality of pairs of optical spectral components with the optical carrier frequency being suppressed, wherein each pair of optical spectral components include a first optical spectral component at a first optical frequency greater than the optical carrier frequency by a corresponding modulating frequency and a second optical spectral component at a second optical frequency less than the optical carrier frequency by the corresponding modulating frequency; and
an optical filtering device coupled to receive the modulated optical beam and to optically filter the modulated optical beam to remove optical spectral components at one side of the optical carrier frequency and to output a filtered optical beam that carries optical spectral components at another side of the optical carrier frequency.
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Abstract
An all optical network for optical signal traffic has at least a first ring with at least one transmitter and one receiver. The first ring includes a plurality of network nodes. At least a first add/drop broadband coupler is coupled to the first ring. The broadband coupler includes an add port and a drop port to add and drop wavelengths to and or from the first ring, a pass-through direction and an add/drop direction. The first add/drop broadband coupler is configured to minimize a pass-through loss in the first ring and is positioned on the first ring.
169 Citations
21 Claims
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1. A device, comprising:
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a Mach-Zehnder interferometer modulator comprising an input port to receive an optical carrier beam at an optical carrier frequency and operable to modulate the optical carrier beam in response to a plurality of modulating signals at different modulating frequencies to produce a modulated optical beam carrying a plurality of pairs of optical spectral components with the optical carrier frequency being suppressed, wherein each pair of optical spectral components include a first optical spectral component at a first optical frequency greater than the optical carrier frequency by a corresponding modulating frequency and a second optical spectral component at a second optical frequency less than the optical carrier frequency by the corresponding modulating frequency; and
an optical filtering device coupled to receive the modulated optical beam and to optically filter the modulated optical beam to remove optical spectral components at one side of the optical carrier frequency and to output a filtered optical beam that carries optical spectral components at another side of the optical carrier frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 18, 19)
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9. A device, comprising:
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a first Mach-Zehnder interferometer modulator to receive a first optical carrier beam at a first optical carrier frequency and to modulate the first optical carrier beam in response to a plurality of first modulating signals at different first modulating frequencies to produce a first modulated optical beam carrying a plurality of pairs of first optical spectral components with the first optical carrier frequency being suppressed, wherein each pair of first optical spectral components include an upper-band optical spectral component at an upper-band optical frequency greater than the first optical carrier frequency by a corresponding first modulating frequency and a lower-band optical spectral component at a lower-band optical frequency less than the first optical carrier frequency by the corresponding first modulating frequency;
a second Mach-Zehnder interferometer modulator to receive a second optical carrier beam at a second optical carrier frequency greater than the first optical carrier frequency and to modulate the second optical carrier beam in response to a plurality of second modulating signals at the different first modulating frequencies to produce a second modulated optical beam carrying a plurality of pairs of second optical spectral components with the second optical carrier frequency being suppressed, wherein each pair of second optical spectral components include an upper-band optical spectral component at an upper-band optical frequency greater than the second optical carrier frequency by a corresponding first modulating frequency and a lower-band optical spectral component at a lower-band optical frequency less than the second optical carrier frequency by the corresponding first modulating frequency, and wherein a lowest spectral component of the second optical spectral components in the second modulated optical beam is greater in frequency than a highest spectral component of the first optical spectral components in the first modulated optical beam;
an optical coupler to combine the first and the second modulated optical beams into a combined modulated optical beam; and
an optical filtering device to receive and to optically filter the combined modulated optical beam to transmit optical spectral components between the first and the second optical carrier frequencies and remove optical spectral components that are greater than the second optical carrier frequency and are less than the first optical carrier frequency. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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20. A method for optical double sideband modulation, comprising:
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modulating an optical carrier beam at an optical carrier frequency in response to a plurality of modulating signals at different modulating frequencies to produce a modulated optical beam carrying a plurality of pairs of optical spectral components with the optical carrier frequency being suppressed, wherein each pair of optical spectral components include a first optical spectral component at a first optical frequency greater than the optical carrier frequency by a corresponding modulating frequency and a second optical spectral component at a second optical frequency less than the optical carrier frequency by the corresponding modulating frequency; and
optically filtering the modulated optical beam to remove optical spectral components at one side of the optical carrier frequency and to output a filtered optical beam carrying optical spectral components at another side of the optical carrier frequency.
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21. A method for optical double sideband modulation, comprising:
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modulating a first optical carrier beam at a first optical carrier frequency in response to a plurality of first modulating signals at different first modulating frequencies to produce a first modulated optical beam carrying a plurality of pairs of first optical spectral components with the first optical carrier frequency being suppressed, wherein each pair of first optical spectral components include an upper-band optical spectral component at an upper-band optical frequency greater than the first optical carrier frequency by a corresponding first modulating frequency and a lower-band optical spectral component at a lower-band optical frequency less than the first optical carrier frequency by the corresponding first modulating frequency;
modulating a second optical carrier beam at a second optical carrier frequency greater than the first optical carrier frequency and to modulate the second optical carrier beam in response to a plurality of second modulating signals at the different first modulating frequencies to produce a second modulated optical beam carrying a plurality of pairs of second optical spectral components with the second optical carrier frequency being suppressed, wherein each pair of second optical spectral components include an upper-band optical spectral component at an upper-band optical frequency greater than the second optical carrier frequency by a corresponding first modulating frequency and a lower-band optical spectral component at a lower-band optical frequency less than the second optical carrier frequency by the corresponding first modulating frequency, and wherein a lowest spectral component of the second optical spectral components in the second modulated optical beam is greater in frequency than a highest spectral component of the first optical spectral components in the first modulated optical beam;
combining the first and the second modulated optical beams into a combined modulated optical beam; and
optically filtering the combined modulated optical beam to transmit optical spectral components between the first and the second optical carrier frequencies and remove optical spectral components that are greater than the second optical carrier frequency and are less than the first optical carrier frequency.
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Specification