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Complexity in pulsed nonlinear laser systems interrogated by permutation entropy
Optics Express
|August 5, 2014
Summary
Permutation entropy (PE) and weighted permutation entropy (WPE) reveal complexity changes in pulsed laser systems. Unexpected inversions in WPE identify transitions from irregular dynamics to pulsed signals with jitter.
Area of Science:
- Nonlinear dynamics
- Laser physics
- Information theory
Background:
- Permutation entropy (PE) is a key measure for nonlinear system complexity.
- PE has been successfully applied to nonlinear laser systems.
- Weighted permutation entropy (WPE) offers an advanced complexity measure.
Purpose of the Study:
- Investigate the behavior of PE and WPE in pulsed nonlinear laser systems.
- Explain the observed inversion of PE and WPE values.
- Utilize WPE to quantify amplitude and timing jitter in pulsed laser outputs.
Main Methods:
- Calculated PE and WPE for nonlinear laser output power sequences.
- Analyzed WPE as a function of delay time for experimental time series.
- Correlated WPE features with simulated data exhibiting controlled jitter and amplitude variations.
Main Results:
- Observed an unexpected inversion in PE and WPE values at characteristic frequencies for pulsed outputs.
- Demonstrated that WPE minimum and peak width indicate amplitude variation and timing jitter.
- Linked WPE behavior to the transition from irregular dynamics to regular pulsed signals.
Conclusions:
- The WPE inversion serves as an indicator for the transition to pulsed laser dynamics.
- WPE analysis provides a quantitative method to assess signal quality in terms of jitter and amplitude variations.
- This approach enhances the characterization of complex dynamics in nonlinear laser systems.
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