Ultrafast Nyquist OTDM demultiplexing using optical Nyquist pulse sampling in an all-optical nonlinear switch

Area of Science:

• Optoelectronics
• Optical Communications
• Nonlinear Optics

Background:

• Optical Time-Division Multiplexing (OTDM) systems require efficient demultiplexing for high data rates.
• Traditional demultiplexing methods face limitations due to spectral overlap and pulse distortion.
• All-optical nonlinear switches are crucial components in advanced optical networks.

Purpose of the Study:

• To propose and demonstrate an ultrahigh-speed demultiplexing technique for OTDM signals.
• To investigate the use of optical Nyquist pulses as both signal and sampling pulses.
• To enhance the tolerance of control pulses to dispersion and nonlinear distortions.

Main Methods:

• Utilizing an optical Nyquist pulse as both the signal and the sampling pulse.
• Employing an all-optical nonlinear switch, specifically a nonlinear optical loop mirror (NOLM).
• Applying the technique to demultiplex Differential Phase Shift Keying (DPSK) and Differential Quadrature Phase Shift Keying (DQPSK) signals from 640 to 40 Gbaud.

Main Results:

• Demonstrated ultrahigh-speed demultiplexing of OTDM signals.
• Achieved significant performance improvement compared to conventional Gaussian control pulses.
• Showcased reduced spectral overlap and enhanced tolerance to dispersion and nonlinear distortions.
• Identified the dependence of the optimal Nyquist control pulse spectral profile on NOLM walk-off properties.

Conclusions:

• Optical Nyquist pulses offer a superior approach for ultrahigh-speed OTDM signal demultiplexing.
• The proposed method enhances system robustness against signal impairments.
• Further optimization of Nyquist pulse profiles can improve demultiplexing efficiency in specific NOLM configurations.