Signal processing apparatus and method for transmitting and receiving coherent parallel optical signals

1. Signal processing apparatus, being configured for transmitting and receiving coherent parallel optical signals, comprising

a transmitter apparatus including a first single soliton micro-resonator device and a modulator device, wherein

the first single soliton micro-resonator device is adapted for creating a single soliton providing a first frequency comb, wherein the first frequency comb provides a plurality of equidistant optical carriers with a frequency spacing corresponding to a free spectral range of the first single soliton micro-resonator device, and

the modulator device is adapted for modulating the optical carriers according to data to be transmitted, and

a receiver apparatus including a coherent receiver device with a plurality of coherent receivers and a local oscillator device providing a plurality of reference optical signals, wherein the coherent receiver device and the local oscillator device are arranged for coherently detecting the transmitted modulated optical carriers, wherein the signal processing apparatus further includes

at least one second single soliton micro-resonator device having a free spectral range being equal or approximated to the free spectral range of the first single soliton micro-resonator device and being adapted for creating at least one single soliton providing at least one second frequency comb, wherein the at least one second frequency comb provides at least one of additional optical carriers and the reference optical signals,

a frequency tuning device being adapted for adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, and

a spectrum measurement unit being adapted for detecting spectral properties of the first and second frequency combs, wherein

the frequency tuning device is adapted for at least one of matching the free spectral ranges of the first and second single soliton micro-resonator devices and adjusting the central frequencies of the first and second frequency combs using acquired data from the spectrum measurement unit, and

the frequency tuning device comprises at least one temperature setting device being adapted for adjusting a temperature of at least one of the first and the second single soliton micro-resonator devices.

2. Signal processing apparatus according to claim 1 , wherein

the central frequencies of at least one of the first and second frequency combs are adjusted using an absolute optical wavelength reference.

3. Signal processing apparatus according to claim 1 , wherein

the free spectral ranges of at least one of the first and second single soliton micro-resonator devices are adjusted using an absolute RF wavelength reference.

4. Signal processing apparatus according to claim 1 , wherein

the at least one second single soliton micro-resonator device is arranged at the transmitter apparatus for creating the second frequency comb providing the additional optical carriers, and

the transmitter apparatus includes a coupling device being arranged for interleaving the optical carriers of the first and second frequency combs.

5. Signal processing apparatus according to claim 4 , further including

a transmitter tuning device being adapted for adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, wherein

the transmitter tuning device is adapted for adjusting at least one of the central frequencies of the first and second frequency combs such that a mutual frequency offset of the first and second frequency combs is equal or approximated to a half free spectral range of the first single soliton micro-resonator device.

6. Signal processing apparatus according to claim 4 , wherein

the coupling device is arranged between the first and at least one second single soliton micro-resonator devices and the modulator device.

7. Signal processing apparatus according to claim 4 , further including

at least one third single soliton micro-resonator device being arranged at the transmitter apparatus and having a free spectral range being equal or approximated to the free spectral range of the first and second single soliton micro-resonator devices and being adapted for creating at least one single soliton providing at least one third frequency comb, wherein the at least one third frequency comb provides additional optical carriers, wherein

the coupling device is arranged for interleaving the optical carriers of the first, second and at least one third frequency combs.

8. Signal processing apparatus according to claim 1 , wherein

the at least one second single soliton micro-resonator device is arranged at the receiver apparatus for creating the second frequency comb providing the reference optical signals.

9. Signal processing apparatus according to claim 8 , further including

a receiver tuning device being adapted for adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, wherein

the receiver tuning device is adapted for adjusting at least one of the central frequencies of the first and second frequency combs such that the central frequencies of the first and second frequency combs are equal or approximated to each other.

10. Signal processing apparatus according to claim 9 , wherein

the receiver tuning device is adapted for adjusting the central frequency of the second frequency comb in dependency on feedback signals from the coherent receiver apparatus.

11. Signal processing apparatus according to claim 8 , further including

at least one third single soliton micro-resonator device being arranged at the receiver apparatus and having a free spectral range being equal or approximated to the free spectral range of the first and second single soliton micro-resonator devices and being adapted for creating at least one single soliton providing at least one third frequency comb, wherein the at least one third frequency comb provides additional reference optical signals, and

a coupling device is arranged for interleaving the reference optical signals of the second and at least one third frequency combs.

12. Signal processing apparatus according to claim 1 , wherein

the at least one second single soliton micro-resonator device is arranged at the transmitter apparatus for creating the second frequency comb providing the additional optical carriers and the transmitter apparatus includes a coupling device being arranged for interleaving the optical carriers of the first and second frequency combs, and

a third single soliton micro-resonator device is arranged at the receiver apparatus for creating a single soliton providing a third frequency comb, wherein the third frequency comb provides the reference optical signals.

13. Signal processing apparatus according to claim 1 , wherein

at least one of the single soliton micro-resonator devices is composed by a continuous wave pumped silicon nitride waveguide and resonator, embedded with silica on a silicon chip.

14. Signal processing apparatus according to claim 1 , wherein

each of the single soliton micro-resonator devices includes a continuous wave (cw) laser arranged for providing cw laser light, and an optical micro-resonator comprising a resonator material, which has a third order (Kerr) nonlinearity and an anomalous resonator dispersion, wherein the cw laser is arranged for coupling the cw laser light into the optical micro-resonator.

15. Transmitter apparatus, being configured for transmitting coherent parallel optical signals, comprising

a first single soliton micro-resonator device being adapted for creating a single soliton providing a first frequency comb, wherein the first frequency comb provides a plurality of equidistant optical carriers with a frequency spacing corresponding to a free spectral range of the first single soliton micro-resonator device,

a second single soliton micro-resonator device having a free spectral range being equal or approximated to the free spectral range of the first single soliton micro-resonator device and being adapted for creating a single soliton providing a second frequency comb, wherein the second frequency comb provides additional optical carriers,

a modulator device being adapted for modulating the optical carriers according to data to be transmitted,

a frequency tuning device being adapted for adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, and

a spectrum measurement unit being adapted for detecting spectral properties of the first and second frequency combs, wherein

the frequency tuning device is adapted for at least one of matching the free spectral ranges of the first and second single soliton micro-resonator devices and adjusting the central frequencies of the first and second frequency combs using acquired data from the spectrum measurement unit, and

the frequency tuning device comprises at least one temperature setting device being adapted for adjusting a temperature of at least one of the first and the second single soliton micro-resonator devices.

16. Receiver apparatus, being configured for receiving coherent parallel optical signals being generated with a first single soliton micro-resonator device for creating a single soliton providing a first frequency comb, wherein the first frequency comb provides a plurality of equidistant optical carriers with a frequency spacing corresponding to a free spectral range of the first single soliton micro-resonator device and a modulator device for modulating the optical carriers according to data to be transmitted, the receiver apparatus comprising

a coherent receiver device with a plurality of coherent receivers, and

a local oscillator device providing a plurality of reference optical signals, wherein

the local oscillator device includes a second single soliton micro-resonator device having a free spectral range being equal or approximated to the free spectral range of the first single soliton micro-resonator device and being adapted for creating a single soliton providing a second frequency comb, wherein the second frequency comb provides the reference optical signals, and

the coherent receiver device and the local oscillator device are arranged for coherently detecting the transmitted modulated optical carriers, wherein the receiver apparatus further comprises

a frequency tuning device being adapted for adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, and

a spectrum measurement unit being adapted for detecting spectral properties of the first and second frequency combs, wherein

the frequency tuning device is adapted for at least one of matching the free spectral ranges of the first and second single soliton micro-resonator devices and adjusting the central frequencies of the first and second frequency combs using acquired data from the spectrum measurement unit, and

the frequency tuning device comprises at least one temperature setting device being adapted for adjusting a temperature of at least one of the first and the second single soliton micro-resonator devices.

17. Signal processing method, including transmitting and receiving coherent parallel optical signals, using a transmitter apparatus with a first single soliton micro-resonator device and a receiver apparatus with a coherent receiver device having a plurality of coherent receivers and a local oscillator device providing a plurality of reference optical signals, comprising the steps of

creating a single soliton with the first single soliton micro-resonator device, the single soliton providing a first frequency comb, wherein the first frequency comb provides a plurality of equidistant optical carriers with a frequency spacing corresponding to a free spectral range of the first single soliton micro-resonator device, and

modulating the optical carriers according to data to be transmitted, and

coherently detecting the transmitted modulated optical carriers with the coherent receiver device and the local oscillator device, wherein

the signal processing method further includes the steps of

creating at least one second frequency comb providing at least one of additional optical carriers and the reference optical signals, the at least one second frequency comb being created with at least one second single soliton micro-resonator device having a free spectral range being equal or approximated to the free spectral range of the first single soliton micro-resonator device and being adapted for creating at least one single soliton providing the at least one second frequency comb,

adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, wherein

spectral properties of the first and second frequency combs are detected and the adjusting step is conducted using the detected spectral properties, and

the adjusting step includes adjusting a temperature of at least one of the first and the second single soliton micro-resonator devices.

18. Signal processing method according to claim 17 , wherein

the central frequencies of at least one of the first and second frequency combs are adjusted using an absolute optical wavelength reference.

19. Signal processing method according to claim 17 , wherein

the free spectral ranges of at least one of the first and second single soliton micro-resonator devices are adjusted using an absolute RF wavelength reference.

20. Signal processing method according to claim 17 , wherein the at least one second single soliton micro-resonator device is arranged at the transmitter apparatus, further including the steps of

creating the second frequency comb providing the additional optical carriers, and

interleaving the optical carriers of the first and second frequency combs with a coupling device.

21. Signal processing method according to claim 20 , further including

adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, such that a mutual frequency offset of the first and second frequency combs is equal or approximated to a half free spectral range of the first single soliton micro-resonator device.

22. Signal processing method according to claim 20 , further including the steps of

creating at least one single soliton providing at least one third frequency comb, wherein the at least one third frequency comb provides additional optical carriers, using at least one third single soliton micro-resonator device being arranged at the transmitter apparatus and having a free spectral range being equal or approximated to the free spectral range of the first and second single soliton micro-resonator devices, wherein

the interleaving step includes interleaving the optical carriers of the first, second and at least one third frequency combs.

23. Signal processing method according to claim 17 , wherein the at least one second single soliton micro-resonator device is arranged at the receiver apparatus, further including the step of

providing the reference optical signals with the at least one second single soliton micro-resonator device.

24. Signal processing method according to claim 23 , further including

adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, such that the central frequencies of the first and second frequency combs are equal or approximated to each other.

25. Signal processing method according to claim 23 , wherein

the central frequency of the second frequency comb is adjusted in dependency on feedback signals from the coherent receiver apparatus.

26. Signal processing method according to claim 23 , further including the steps of

creating at least one single soliton providing at least one third frequency comb with at least one third single soliton micro-resonator device being arranged at the receiver apparatus and having a free spectral range being equal or approximated to the free spectral range of the first and second single soliton micro-resonator devices, wherein the at least one third frequency comb provides additional reference optical signals, and

interleaving the reference optical signals of the second and at least one third frequency combs.

27. Signal processing method according to claim 17 , including the steps of

creating the second frequency comb providing the additional optical carriers with the at least one second single soliton micro-resonator device being arranged at the transmitter apparatus,

interleaving the optical carriers of the first and second frequency combs, and

creating a single soliton providing a third frequency comb with a third single soliton micro-resonator device being arranged at the receiver apparatus, wherein the third frequency comb provides the reference optical signals.

28. Transmitting method for transmitting coherent parallel optical signals, comprising the steps of

creating a single soliton providing a first frequency comb with a first single soliton micro-resonator device, wherein the first frequency comb provides a plurality of equidistant optical carriers with a frequency spacing corresponding to a free spectral range of the first single soliton micro-resonator device,

creating a single soliton providing a second frequency comb with a second single soliton micro-resonator device having a free spectral range being equal or approximated to the free spectral range of the first single soliton micro-resonator device, wherein the second frequency comb provides additional optical carriers,

modulating the optical carriers according to data to be transmitted, and

transmitting the modulated optical carriers to a communication channel, including the further steps of

adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, wherein

spectral properties of the first and second frequency combs are detected and the adjusting step is conducted using the detected spectral properties, and

the adjusting step includes adjusting a temperature of at least one of the first and the second single soliton micro-resonator devices.

29. Receiving method for receiving coherent parallel optical signals being generated with a first single soliton micro-resonator device for creating a single soliton providing a first frequency comb, wherein the first frequency comb provides a plurality of equidistant optical carriers with a frequency spacing corresponding to a free spectral range of the first single soliton micro-resonator device and a modulator device for modulating the optical carriers according to data to be transmitted, comprising the steps of

coherently detecting the transmitted modulated optical carriers with a coherent receiver device having a plurality of coherent receivers and with a local oscillator device, wherein

the local oscillator device includes a second single soliton micro-resonator device having a free spectral range being equal or approximated to the free spectral range of the first single soliton micro-resonator device and being adapted for creating a single soliton providing a second frequency comb, wherein the second frequency comb provides the reference optical signals, including the further steps of

adjusting at least one of a central frequency of at least one of the first and second frequency combs and the free spectral ranges of at least one of the first and second single soliton micro-resonator devices, wherein

spectral properties of the first and second frequency combs are detected and the adjusting step is conducted using the detected spectral properties, and

the adjusting step includes adjusting a temperature of at least one of the first and the second single soliton micro-resonator devices.