Antiphase chaotic synchronization enhancement in a vertical cavity surface emitting laser

Area of Science:

• Nonlinear optics
• Semiconductor lasers
• Chaos theory

Background:

• Vertical cavity surface emitting lasers (VCSELs) are crucial optoelectronic devices.
• Nonlinear dynamics in VCSELs, particularly polarization dynamics, are complex.
• Optical feedback (OF) is known to influence laser behavior.

Purpose of the Study:

• To experimentally investigate the effect of optical feedback on nonlinear polarization dynamics in VCSELs.
• To analyze antiphase chaos synchronization and mode hopping under varying feedback conditions.
• To understand the role of polarization angle and bias current in VCSEL dynamics.

Main Methods:

• Utilized a VCSEL with controlled optical feedback.
• Employed a rotating orthogonal polarization as an external parameter to induce chaos.
• Measured the intensity of two linear polarization modes across a range of bias currents and optical feedback angles.

Main Results:

• Antiphase chaotic synchronization is enhanced with increasing optical feedback polarization angle.
• Polarization modes exhibited antiphase synchronization without time delay at specific bias currents.
• Synchronization quality deteriorated at higher bias currents and specific angles due to power mode differences, disrupting mode-computation effects.
• Polarization switching and mode hopping were observed, correlating with improved synchronization.

Conclusions:

• Optical feedback significantly influences VCSEL polarization dynamics, enhancing chaotic synchronization.
• The angle of optical feedback and bias current are critical parameters affecting synchronization quality and stability.
• Power mode differences can disrupt synchronization, highlighting the complex interplay of factors in VCSEL chaotic dynamics.