320 Gb/s Nyquist OTDM received by polarization-insensitive time-domain OFT

Area of Science:

• Optical communications
• Signal processing
• Photonics

Background:

• High-speed optical transmission systems require efficient signal generation and reception techniques.
• Optical Time-Division Multiplexing (OTDM) is a key technology for increasing data rates.
• Nyquist filtering is crucial for maximizing spectral efficiency in OTDM systems.

Purpose of the Study:

• To demonstrate the generation of a 320 Gb/s Nyquist-OTDM signal.
• To showcase a polarization-insensitive reception method for Nyquist-OTDM signals.
• To investigate the conversion of Nyquist-OTDM signals to Orthogonal Frequency Division Multiplexing (OFDM) signals for simplified demultiplexing.

Main Methods:

• Generation of a 320 Gb/s Nyquist-OTDM signal via rectangular filtering of an RZ-OTDM signal.
• Reception using polarization-insensitive time-domain optical Fourier transformation (TD-OFT) with four-wave mixing (FWM).
• Passive filtering for subcarrier extraction after TD-OFT conversion to an OFDM signal.

Main Results:

• Successful generation of a 320 Gb/s Nyquist-OTDM signal.
• Nyquist-OTDM signal converted to an OFDM signal with sinc-shaped spectra per subcarrier via TD-OFT.
• Demonstrated polarization sensitivity of less than 0.5 dB in the OTDM receiver using a polarization diversity scheme.
• Simplified subcarrier extraction using passive filtering due to increased subcarrier spacing.

Conclusions:

• The study successfully demonstrated a high-speed Nyquist-OTDM signal generation and reception technique.
• TD-OFT enables efficient conversion of Nyquist-OTDM signals to OFDM, facilitating simpler receiver designs.
• The polarization-insensitive TD-OFT receiver shows high performance, crucial for robust optical communication systems.