Simplified adaptive polarization controller controlled by an alpha-beta filter for the self-coherent communication...

Area of Science:

• Optical Engineering
• Photonics
• Telecommunications

Background:

• Carrier fading in self-homodyne coherent detection (SHCD) systems necessitates adaptive polarization control (APC).
• Existing APCs often require complex designs and control algorithms.
• Polarization stabilization is critical for maintaining signal integrity in optical communication systems.

Purpose of the Study:

• To propose a simplified adaptive polarization controller (APC) design for SHCD systems.
• To investigate the efficacy of an alpha-beta filter for APC control.
• To demonstrate reset-free polarization stabilization using a single phase shifter.

Main Methods:

• A simplified APC was designed on an X-cut, Y-propagating lithium niobate platform.
• An alpha-beta filter was employed for the APC's control mechanism.
• Performance was evaluated against the greedy linear descent (GLD) algorithm.

Main Results:

• The alpha-beta filter demonstrated superior tracking limit and stability compared to GLD.
• The designed APC achieved reset-free polarization stabilization with a single phase shifter.
• The system successfully mitigated rapid polarization changes (100 krad/s) over 10 km fiber.

Conclusions:

• The proposed simplified APC with an alpha-beta filter offers an effective solution for polarization stabilization in SHCD systems.
• This approach enables robust performance under challenging polarization rotation conditions.
• The integration of the alpha-beta filter represents a novel advancement in polarization control technology.