All-optical technique for modulation format conversion from on-off-keying to alternate-mark-inversion

Area of Science:

• Photonics and Optical Communications
• Semiconductor Devices
• Signal Processing

Background:

• High-speed optical communication systems require efficient modulation format conversion.
• Semiconductor optical amplifiers (SOAs) are key components in all-optical signal processing.
• Mach-Zehnder interferometers (MZIs) offer versatile platforms for optical signal manipulation.

Purpose of the Study:

• To propose and numerically investigate a novel all-optical converter for on-off-keying (OOK) to alternate-mark-inversion (AMI) modulation format.
• To achieve high-speed operation at 40 Gbps.
• To analyze the performance and characteristics of the proposed device.

Main Methods:

• Utilizing a semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (MZI).
• Performing numerical simulations to investigate the converter's operation.
• Modeling the device as a pulse subtractor to achieve phase inversion.

Main Results:

• Demonstrated that the SOA-MZI functions as an effective pulse subtractor.
• Achieved perfectly phase-inverted pulses in the absence of patterning.
• Quantified the impact of patterning on output phase modulation using a phase compression factor.

Conclusions:

• The proposed SOA-MZI is a viable solution for all-optical OOK to AMI conversion at 40 Gbps.
• The device exhibits robust phase inversion capabilities.
• Understanding patterning effects is crucial for optimizing phase modulation in such converters.