Simultaneous demonstration on all-optical digital encoder and comparator at 40 Gb/s with semiconductor optical...

Area of Science:

• Optoelectronics
• Digital Logic Circuits
• Optical Signal Processing

Background:

• High-speed optical data processing is crucial for modern telecommunications.
• Implementing complex logic functions all-optically can overcome electronic bottlenecks.
• Semiconductor optical amplifiers (SOAs) offer promising platforms for all-optical signal manipulation.

Purpose of the Study:

• To propose and experimentally demonstrate an all-optical encoder and comparator.
• To achieve simultaneous implementation of multiple logic functions at high data rates.
• To investigate the performance of cross gain modulation (XGM) and four wave mixing (FWM) for these operations.

Main Methods:

• Utilized three parallel semiconductor optical amplifiers (SOAs).
• Employed cross gain modulation (XGM) for three logic functions (AB, AB, AB).
• Employed four wave mixing (FWM) for one logic function (AB).
• Achieved a mixed logic function (AOmicronB) by combining XGM and FWM outputs.
• Implemented a detuning filter to enhance output performance.

Main Results:

• Simultaneously realized five digital logic functions (AB, AB, AB, AB, AOmicronB) for RZ data streams at 40Gb/s.
• Achieved output extinction ratios (ER) above 10dB for XGM-based operations.
• Obtained ER around 8 dB for FWM-based operations.
• Observed wide and clear eye patterns for all five logic outputs, indicating high signal quality.

Conclusions:

• The proposed all-optical scheme effectively performs encoding and comparison functions at 40Gb/s.
• XGM and FWM in parallel SOAs provide a viable method for complex all-optical logic operations.
• The demonstrated system shows potential for high-speed optical signal processing applications.