Abstract
We demonstrate a Mach-Zehnder (MZ) architecture for polarization-insensitive (PI) fiber optical parametric amplifiers (FOPA) and confirm that it improves both noise figure and nonlinear crosstalk as compared to PI-FOPAs employing a polarization diversity loop. We characterize the MZ PI-FOPA by employing it to amplify 17x100 GHz-spaced WDM channels including a 35 GBaud PDM-QPSK signal between 1528.0 and 1540.56 nm with a net gain between 15.5 and 24 dB. We demonstrate the record low PI-FOPA noise figure down to 4.4 dB, and a noise figure below 6 dB across all amplified channels for the total signal output power up to 13 dBm. The latter demonstrates an improvement in the nonlinear crosstalk tolerance by $\sim$7 dB as compared to previously reported looped PI-FOPAs.
| Original language | English |
|---|---|
| Number of pages | 9 |
| Journal | Journal of Lightwave Technology |
| Early online date | 1 Dec 2025 |
| DOIs | |
| Publication status | E-pub ahead of print - 1 Dec 2025 |
Bibliographical note
For the purpose of open access, the author(s) has applied a Creative Commons Attribution (CC BY) license to any Accepted Manuscript version arising.Funding
This work was supported in part by U.K. Engineering and Physical Sciences Research Council under Grants EP/R024057/1 (FPA-ROCS), EP/X031918/1 (IMPAC) and EP/M005283/1 (UPON) and in part by the UKRI Future Leaders Fellowship under Grant MR/T041218/1.
Keywords
- Optical fiber amplifiers
- Optical fibers
- Gain
- Optical fiber polarization
- Wavelength division multiplexing
- Stimulated emission
- Optical pumping
- Nonlinear optics
- Optical polarization
- Optical fiber communication