Quantifying the synchronization of the spikes emitted by coupled lasers

Area of Science:

• Physics
• Nonlinear Dynamics
• Optical Engineering

Background:

• Synchronization is a widespread phenomenon in nature, but quantifying it in noisy signals remains difficult.
• Semiconductor lasers offer a controllable and inexpensive platform for studying nonlinear dynamics and synchronization.
• Optically coupled lasers exhibit synchronization with a lag due to signal travel time.

Purpose of the Study:

• To develop and validate a method for accurately quantifying spike synchronization in optically coupled lasers.
• To overcome limitations of traditional synchronization measures that are sensitive to noise and fast fluctuations.
• To identify leading and lagging lasers based on spike timing analysis.

Main Methods:

• Experimental analysis of two mutually optically coupled semiconductor lasers.
• Focusing on the timing of intensity spikes rather than continuous intensity fluctuations.
• Application of event synchronization measures to analyze spike coincidence.

Main Results:

• Event synchronization measures effectively quantify the synchronicity of spikes between coupled lasers.
• These measures are robust against fast, irregular fluctuations present in the laser intensity signals.
• The leading and lagging laser can be accurately identified using spike timing analysis.

Conclusions:

• Event synchronization provides a precise method for analyzing lag synchronization in semiconductor lasers.
• This approach enhances the understanding and quantification of synchronization phenomena in complex systems.
• The developed method offers a reliable tool for characterizing directional coupling and lead-lag relationships in dynamical systems.