Polarization-diversity receiver using remotely delivered local oscillator without optical polarization control

Area of Science:

• Photonics and Optical Communications
• Integrated Optics
• Digital Signal Processing

Background:

• Silicon photonics coherent transceivers require integrated lasers, increasing cost, footprint, and power consumption for short-reach optical interconnects.
• Remotely delivered local oscillator (LO) lasers simplify transceiver design but necessitate complex adaptive polarization controllers (APCs) to manage polarization wandering.

Purpose of the Study:

• To propose a novel hybrid receiver architecture for polarization-diversity coherent detection.
• To eliminate the need for optical polarization control for remotely delivered LO signals in coherent transceivers.

Main Methods:

• Development of a hybrid single-polarization coherent receiver combined with a Stokes vector receiver (SVR).
• Implementation of a polarization-diversity coherent detection scheme without active optical polarization control.
• Experimental validation using a 400-Gb/s dual-polarization 64-QAM signal transmitted over 80-km of optical fiber.

Main Results:

• Successful reception of a 400-Gb/s dual-polarization constellation-shaped 64-QAM signal.
• Demonstration of effective coherent detection without requiring optical polarization control for the LO.
• Validation of the proposed hybrid receiver's performance over a significant fiber link.

Conclusions:

• The proposed hybrid receiver effectively enables polarization-diversity coherent detection without optical polarization control for remotely delivered LOs.
• This approach simplifies coherent transceiver design, reducing cost and complexity for short-reach optical interconnects.
• The successful demonstration paves the way for more efficient and scalable optical communication systems.