Apparatus and method for shifting a frequency of an optical signal
US11588557B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 2, 2022 |
| Grant date | Feb 21, 2023 |
| Priority date | — |
| Expiry date | Mar 2, 2042 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/50
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A system and method for applying a time-varying phase shift to an optical signal is described. Such a phase shift results in a frequency shift of the optical signal, which can be useful for instance in sensing applications. The design uses cross phase modulation (XPM) in a nonlinear medium such as optical fiber. The pump producing the XPM experiences a change in energy along the medium, for instance due to loss. The pump and signal have mismatched group velocities such that they walk-off each other in time, and the pump pulse repetition rate is chosen so that it has a specific relationship with respect to the walk-off. The design is compatible with very low signal loss and does not require high fidelity electrical control signals. It is capable of high-efficiency one-directional serrodyne frequency shifts, as well as producing symmetric frequency shifts. It can also be made polarization independent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.