Highly precise timing alignment of multi-wavelength interleaved cavity-less pulse sources with FROG

Area of Science:

• Optics and Photonics
• Optical Engineering

Background:

• Multi-wavelength interleaved (MWI) pulse sources require precise temporal alignment between channels for optimal performance.
• Existing alignment methods face challenges in achieving the necessary accuracy and resolution.

Purpose of the Study:

• To introduce a novel, highly precise method for aligning MWI pulse sources.
• To demonstrate the effectiveness of frequency-resolved optical gating (FROG) for temporal alignment of MWI sources.

Main Methods:

• Utilizing frequency-resolved optical gating (FROG) to obtain two-dimensional time-and-frequency domain pulse information.
• Employing FROG measurements to intuitively identify and correct time mismatches between MWI channels.
• Achieving sub-picosecond resolution in temporal alignment.

Main Results:

• Successfully aligned MWI pulse sources with repetition rates of 20.8 GHz (four wavelengths) and 41.6 GHz (eight wavelengths).
• Demonstrated accurate and intuitive identification of time mismatches using FROG.
• Achieved sub-picosecond temporal alignment resolution.

Conclusions:

• The proposed FROG-based method offers a robust solution for precisely aligning MWI pulse sources.
• This advancement is critical for applications such as photonic analog-digital converters (PADC) and high-speed optical communications.
• The method enables efficient and accurate temporal synchronization of complex optical pulse systems.