Simultaneous WDM signal detection realized by ultrafast field sampling

Area of Science:

• Optical Communications
• Signal Processing

Background:

• Wavelength-division multiplexing (WDM) is crucial for high-capacity optical networks.
• Current WDM monitoring often requires complex demultiplexing stages.
• Accurate reconstruction of WDM channel fields and phase relationships is challenging.

Purpose of the Study:

• To introduce a novel WDM signal detection technique using ultrafast field sampling.
• To demonstrate simultaneous reconstruction of individual WDM channel fields and their mutual phase relationships.
• To explore potential applications in advanced WDM monitoring and digital coherent detection.

Main Methods:

• Utilizing ultrafast field sampling to capture the total WDM signal field.
• Employing electrical post-processing for digital domain filtering and channel separation.
• Implementing a dual-channel field sampling system with polarization diversity for demonstration.

Main Results:

• Successfully demonstrated simultaneous monitoring of a two-channel WDM signal with independent polarization states.
• Experimentally verified that reconstructed fields accurately preserve the mutual phase relationship of original fields.
• The technique is scalable to N-channel WDM systems using an N-channel sampling system.

Conclusions:

• The proposed 'field sensitive' WDM detection technique offers a novel approach to WDM signal analysis.
• This method eliminates the need for wavelength demultiplexing during the sampling process.
• Potential applications include advanced WDM monitoring and electrical compensation of crosstalk in digital coherent systems.