All-optical rectangular-QAM regenerators based on phase-preserving I/Q shaping
Abstract
We put forward a new all-optical I/Q regeneration scheme for quadrature amplitude modulation (QAM) signals with rectangular constellation. In the proposed scheme, two phase-preserving amplitude and phase shift key (PP-APSK) regeneration units are built up by optimizing the nonlinear amplified fiber loop mirror. The phase-preserving amplitude regeneration characteristics obtained by simulation are identical with the theoretical results. Our simulation shows that the maximum noise reduction ratios of the proposed regenerators are up to 3 dB, 6.9 dB, and 4.5 dB at the input optical signal-to-noise ratio of about 26 dB for 8QAM, 16QAM and 32QAM signals, respectively.
- Publication:
-
Optics Communications
- Pub Date:
- July 2020
- DOI:
- 10.1016/j.optcom.2020.125634
- Bibcode:
- 2020OptCo.46725634S
- Keywords:
-
- All-optical regeneration;
- Quadrature amplitude modulation (QAM);
- Optical phase conjugator (OPC);
- Phase-preserving amplitude and phase shift key (PP-APSK)