Study of a Crosstalk Suppression Scheme Based on Double-Stage Semiconductor Optical Amplifiers

Area of Science:

• Optical communication networks
• Signal processing in optical systems

Background:

• Wavelength and space division multiplexing (WDM/SDM) optical networks require effective crosstalk suppression to enhance node performance.
• Current methods for crosstalk mitigation often face limitations in preserving signal wavelength integrity.

Purpose of the Study:

• To propose and investigate a novel all-optical crosstalk suppression scheme using a double-stage semiconductor optical amplifier (SOA) setup.
• To optimize the wavelength position of the degenerate pump in optical phase conjugation (OPC) for maximizing signal-to-crosstalk ratio (SXR).

Main Methods:

• A simulation-based approach was employed to evaluate the performance of the double-stage SOA scheme.
• The scheme was tested for 20 Gb/s quadrature phase shift keying (QPSK) signals, analyzing various input SXR ranges and crosstalk wavelength deviations.
• Optimization of the degenerate pump's wavelength in the optical phase conjugation (OPC) process was a key methodological aspect.

Main Results:

• The proposed double-stage SOA scheme demonstrates effective wavelength-preserving crosstalk suppression.
• An equivalent SXR improvement of 1.5 dB was achieved for identical-frequency crosstalk with an input SXR of 10 dB.
• The scheme's performance was validated across different input SXR levels and crosstalk wavelength deviations.

Conclusions:

• The double-stage SOA scheme offers a viable solution for improving SXR in optical networks.
• This approach is particularly well-suited for applications in few-mode fiber systems and advanced optical networks.
• The optimized OPC pump wavelength is crucial for maximizing the effectiveness of the crosstalk suppression.