Data transmission rates from optical sources
Apparatus including an optical signal generator, a data transmission path, and an optical signal receiver. Optical signal generator includes a coherent light source for generating a spectrum of carrier signals at different carrier frequencies, an optical demultiplexer that receives and separates the different carrier signals into separate optical paths, a pair of optical modulators located in each of the separate optical paths to modulate each different carrier signal with a data signal and produce an upper and lower sideband pair at each of the different carrier frequencies, and an optical interleaver to combine the upper and lower sideband pairs into an optical super-channel of interleaved sub-bands. Optical signal receiver includes a demodulator for extracting the data signals. Optical modulators are configured to reuse each carrier signal to transmit different data in each of the upper sideband and the lower sideband and increase the capacity of the super-channel. Also a method.
1 . A communication system, the communication system comprising:
an optical signal generator, including:
a coherent light source comprising a single laser that produces a continuous wave laser beam at a laser frequency and a micro-ring resonator that receives the laser beam from the single laser, the single laser being tuned to the micro-ring resonator to generate a micro-comb spectrum of different carrier signals at different carrier frequencies;
an optical demultiplexer that receives and separates the different carrier signals into separate optical paths, respectively;
a pair of optical modulators respectively located in each separate optical path to respectively modulate an upper sideband and a lower sideband of each different carrier signal with respective data signals and produce a modulated upper and lower sideband pair at each of the different carrier frequencies; and
an optical interleaver to combine the modulated upper and lower sideband pairs into an optical super-channel of interleaved sub-bands;
a data transmission path for receiving and transmitting the super-channel; and
a coherent optical signal receiver, including a demodulator for extracting data signals from the interleaved sub-bands of the optical super-channel;
wherein each pair of optical modulators is configured to use each carrier signal to transmit different data in each of the upper sideband and the lower sideband and thereby increase a capacity of the optical super-channel.
2 . The communication system according to claim 1 , further comprising:
an optical filter between the data transmission path and the demodulator to selectively filter the upper sideband or the lower sideband of each carrier signal to a separate coherent detection stage.
3 . The communication system according to claim 2 , wherein each of the interleaved sub-bands has a sub-band bandwidth, and the optical filter has a passband greater than or equal to the sub-band bandwidth.
4 . The communication system according to claim 3 , wherein the passband of the optical filter is equal to the sub-band bandwidth.
5 . The communication system according to claim 3 , wherein the passband of the optical filter is less than 3 times the sub-band bandwidth.
6 . The communication system according to claim 3 , wherein the optical filter has a roll-off greater than 20 dB at less than 1% of the sub-band bandwidth.
7 . The communication system according to claim 3 , wherein the optical interleaver spaces the interleaved sub-bands at intervals equal to twice the sub-band bandwidth.
8 . The communication system according to claim 1 , wherein the data transmission path includes an optical fibre link.
9 . A method, comprising:
at an optical signal generator,
producing, by a single laser, a continuous wave laser beam at a laser frequency;
receiving a laser beam from the single laser at a micro-ring resonator, the single laser being tuned to the micro-ring resonator to generate a micro-comb spectrum of different carrier signals at different carrier frequencies;
receiving and separating the different carrier signals into separate optical paths at an optical demultiplexer, respectively;
at a pair of optical modulators respectively located in each separate optical path, respectively modulating an upper sideband and a lower sideband of each different carrier signal with respective data signals and producing a modulated upper and lower sideband pair at each of the different carrier frequencies; and
at an optical multiplexer, combining the modulated upper and lower sideband pairs into an optical super-channel of interleaved sub-bands,
transmitting the optical super-channel along a data transmission path; and
at a coherent optical signal receiver,
receiving the optical super-channel along the data transmission path; and
extracting data signals from the interleaved sub-bands of the optical super-channel at a demodulator;
wherein each pair of optical modulators are configured to use each carrier signal to transmit different data in each of the upper sideband and the lower sideband and thereby increase a capacity of the optical super-channel.
10 . The method according to claim 9 , and further comprising:
at an optical filter between the data transmission path and the demodulator, selectively filtering the upper sideband or the lower sideband of each carrier signal to a separate coherent detection stage.
11 . The method according to claim 10 , wherein each of the interleaved sub-bands has a sub-band bandwidth, and the optical filter has a passband greater than or equal to the sub-band bandwidth.
12 . The method according to claim 11 , wherein the passband of the optical filter is equal to sub-band bandwidth.
13 . The method according to claim 11 , wherein the passband of the optical filter is less than 3 times the sub-band bandwidth.
14 . The method according to claim 11 , wherein the optical filter has a roll-off greater than 20 dB at less than 1% of the sub-band bandwidth.
15 . The method according to claim 11 , wherein:
the optical interleaver spaces the interleaved sub-bands at intervals equal to twice the sub-band bandwidth.
16 . The method according to claim 9 , wherein the data transmission path includes an optical fibre link.
17 . An optical signal generator, comprising:
a coherent light source comprising a single laser that produces a continuous wave laser beam at a laser frequency and a micro-ring resonator that receives the laser beam from the single laser, the single laser being tuned to the micro-ring resonator to generate a micro-comb spectrum of different carrier signals at different carrier frequencies;
an optical demultiplexer that receives and separates the different carrier signals into separate optical paths, respectively;
a pair of optical modulators respectively located in each separate optical path to respectively modulate an upper sideband and a lower sideband of each different carrier signal with respective data signals and produce a modulated upper and lower sideband pair at each of the different carrier frequencies; and
an optical interleaver to combine the modulated upper and lower sideband pairs into an optical super-channel of interleaved sub-bands;
wherein each pair of optical modulators is configured to use each carrier signal to transmit different data in each of the upper sideband and the lower sideband and thereby increase a capacity of the optical super-channel.
18 . The optical signal generator according to claim 17 , wherein the data transmission path includes an optical fibre link.