Subharmonic anti-phase dynamics in coupled mode-locked semiconductor lasers

Area of Science:

• Optics and Photonics
• Semiconductor Laser Physics

Background:

• Mode-locked semiconductor lasers are crucial for generating ultrashort optical pulses.
• Understanding coupled laser dynamics is essential for advanced optical systems.

Purpose of the Study:

• To investigate the subharmonic operation regime in coupled mode-locked semiconductor lasers.
• To characterize novel pulse dynamics and synchronization phenomena.

Main Methods:

• Experimental investigation of two coupled mode-locked semiconductor lasers.
• Analysis of pulse characteristics, frequency relationships, and synchronization patterns.

Main Results:

• Demonstrated subharmonic mode-locking where lasers pulsate at half the fundamental frequency.
• Observed pulses with doubled energy and reduced duration compared to solitary lasers.
• Identified bistability, perfect, and delayed synchronization, alongside fractional harmonic mode-locking (3/2, 5/2).

Conclusions:

• Coupled mode-locked lasers exhibit rich dynamics, including robust subharmonic operation.
• The findings offer new possibilities for generating high-energy, short-duration pulses.
• Synchronization phenomena in coupled lasers are controllable and resilient to noise.