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EP-4737990-A1 - METHOD, APPARATUS AND COMPUTER PROGRAM FOR PHASE ADJUSTMENT OF SIGNALS OF A PHOTONIC PROCESSOR

EP4737990A1EP 4737990 A1EP4737990 A1EP 4737990A1EP-4737990-A1

Abstract

Provided is a method for phase adjustment. The method includes receiving data indicating a characteristic of photonic output signals of a photonic processor. The method further includes generating a control signal for controlling adjustment of a phase of at least one photonic processing signal based on the characteristic according to a predetermined logic.

Inventors

  • LITVIN, Ihar
  • NÖTZEL, Janis
  • Geitz, Marc

Assignees

  • Deutsche Telekom AG
  • Technische Universität München

Dates

Publication Date
20260506
Application Date
20241031

Claims (15)

  1. A method (100) for phase adjustment, the method (100) comprising: receiving (110) data indicating a characteristic (310, 320) of photonic output signals (930; 940) of a photonic processor (420; 900); generating (120) a control signal for controlling adjustment of a phase of at least one photonic processing signal (910) based on the characteristic (310, 320) according to a predetermined logic.
  2. The method (100) of claim 1, wherein the characteristic (310, 320) of the photonic output signals (930; 940) comprises output powers of the photonic output signals (930; 940), wherein the predetermined logic comprises comparing the output powers, and wherein the control signal is generated based on the comparison of the output powers.
  3. The method (100) of claim 2, wherein the predetermined logic comprises determining, based on the comparison of the output powers, a direction for the adjustment of the phase by a predetermined phase increment, wherein the control signal is generated to control adjustment of the phase by the predetermined phase increment in the determined direction.
  4. The method (100) of claim 2, wherein the predetermined logic comprises determining, based on the comparison of the output powers, a phase shift for the adjustment of the phase, wherein the control signal is generated to control adjustment of the phase by the determined phase shift.
  5. The method (100) of any one of claims 1 to 4, wherein the photonic output signals (930; 940) and the at least one photonic processing signal (910) have a same photonic characteristic, and wherein the at least one photonic processing signal (910) is a photonic input signal for the photonic processor (420; 900), or a photonic signal processed in the photonic processor (420; 900).
  6. The method (100) of any one of claims 1 to 4, wherein the photonic output signals (930) are based on at least one auxiliary photonic processing signal (920) processed along the same photonic signal path of the photonic processor (420; 900) as the at least one photonic processing signal (910), wherein the at least one photonic processing signal (910) has a first photonic characteristic, and wherein the photonic output signals (930) and the at least one auxiliary photonic processing signal (920) have a second photonic characteristic different from the first photonic characteristic.
  7. The method (100) of any one of claims 1 to 6, wherein the control signal is configured to control a pairwise adjustment of the phase of at least two photonic processing signals (910) based on which at least two photonic output signals (930; 940) are generated, wherein the pairwise adjustment comprises applying an alternating phase-shift to the at least two photonic processing signals (910).
  8. An apparatus (400) for phase adjustment, the apparatus comprising circuitry (410) configured to carry out the method of any one of claims 1 to 7.
  9. The apparatus (400) of claim 8, further comprising measurement circuitry (450) configured to measure the characteristic and generate the data indicating the characteristic.
  10. The apparatus (400) of claim 8 or 9, further comprising: at least one phase-shifter (460; 510; 710) for the at least one photonic processing signal (910), wherein the circuitry (410) is further configured to output the control signal to the at least one phase-shifter (460; 510; 710).
  11. The apparatus (400) of claim 10, wherein the at least one phase-shifter (460; 710) is external to the photonic processor (420; 900) and configured to adjust the phase of the at least one photonic processing signal (910) before being input into the photonic processor (420; 900).
  12. The apparatus (400) of any one of claims 8 to 11, further comprising the photonic processor (420; 900).
  13. The apparatus (400) of claim 12, further comprising: a plurality of photonic input fibers (430) coupled to inputs of the photonic processor (420; 900); a plurality of photonic output fibers (440) coupled to outputs of the photonic processor (420; 900) and configured to transmit the photonic output signals (930; 940), wherein the adjustment of the phase is for compensating a disturbance that is imparted to at least one of the plurality of photonic input fibers (430) and the plurality of photonic output fibers (440).
  14. The apparatus (400) of claim 12 or 13, wherein the at least one phase-shifter (510) is internal to the photonic processor (420; 900) and configured to adjust the phase of the at least one photonic processing signal (910) in the photonic processor.
  15. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method of any one of claims 1 to 7.

Description

Field The present disclosure relates to photonic processing and in particular to a method for phase adjustment, an apparatus for phase adjustment, and a computer program. Background Photonic processing may relate to a type of computing in which, instead of electric signals, light signals (i.e., photons) may be used. A photonic processor may relate to a type of computing device that uses light instead of electrons to perform data processing. By leveraging the speed and bandwidth of light, photonic processors may be able to process information faster than traditional electronic processors, potentially enabling more efficient and faster computations. Photonic processors may use optical components such as lasers, waveguides, photodetectors, interferometers, beam splitters, and the like, to manipulate and transmit data. Photonic processors may especially be suitable for tasks requiring massive data transmission, like in telecommunications and high-performance computing. Also, it may be possible to reduce energy consumption compared to electronic processors, making them an attractive solution for future computing technologies. There may be a demand for improved stabilization of photonic processors. Summary This demand may be satisfied by the subject-matter of the independent claims. Further embodiments or examples are given by the dependent claims, the drawings, and the following description. According to a first aspect, the disclosure provides a method for phase adjustment. The method comprises receiving data indicating a characteristic of photonic output signals of a photonic processor. The method further comprises generating a control signal for controlling adjustment of a phase of at least one photonic processing signal based on the characteristic according to a predetermined logic. Thereby, phase stabilization for a photonic processor may be provided and computing of the photonic processor may be improved. Thereby, significant boost in performance for integrated optical devices used in quantum computing, quantum communication, quantum detection, and specialized classical operations may be achieved. However, without proper stabilization, these devices would potentially fail to function effectively. In some examples, the characteristic of the photonic output signals comprises output powers of the photonic output signals. The predetermined logic comprises comparing the output powers. The control signal is generated based on the comparison of the output powers. Thereby, a dependency of the output power and the phase may be utilized. In some examples, the predetermined logic comprises determining, based on the comparison of the output powers, a direction for the adjustment of the phase by a predetermined phase increment. The control signal is generated to control adjustment of the phase by the predetermined phase increment in the determined direction. Thereby, a feedback loop may be provided to adjust the phase. In some examples, the predetermined logic comprises determining, based on the comparison of the output powers, a phase shift for the adjustment of the phase. The control signal is generated to control adjustment of the phase by the determined phase shift. Thereby, the phase-shift may be (directly) calculated and adjusted accordingly. In some examples, the at least one photonic processing signal carries data to be processed by the photonic processor. Thereby, improved processing may be achieved. In some examples, the photonic output signals and the at least one photonic processing signal have a same photonic characteristic. The at least one photonic processing signal is a photonic input signal for the photonic processor or a photonic signal processed in the photonic processor. Thereby, the photonic output signals may be generated based on the at least one photonic processing signal and no additional photonic signals may be needed. In some examples, the photonic output signals are based on at least one auxiliary photonic processing signal processed along the same photonic signal path of the photonic processor as the at least one photonic processing signal. The at least one photonic processing signal has a first photonic characteristic. The photonic output signals and the at least one auxiliary photonic processing signal have a second photonic characteristic different from the first photonic characteristic. Thereby, an auxiliary signal may be used for adjusting the photonic processing signal such that more processing outputs can be achieved. Otherwise, if the photonic output signals and the photonic processing signals have the same photonic characteristic(s), at least one photonic output signal may be needed for feedback control instead of processing. In some examples, the control signal is configured to control a pairwise adjustment of the phase of at least two photonic processing signals based on which at least two photonic output signals are generated. The pairwise adjustment comprises applying an alterna