Bistability and all-optical switching in semiconductor ring lasers.

Area of Science:

• Optoelectronics
• Nonlinear Dynamics
• Quantum Optics

Background:

• Semiconductor ring lasers exhibit complex dynamics due to competing clockwise and counter-clockwise modes.
• A bistable regime with coexisting quasi-unidirectional modes occurs at high pumping levels.
• This bistability, driven by cross-gain saturation, is a candidate for optical data storage.

Purpose of the Study:

• To analyze the response time of semiconductor ring lasers when switching between counter-propagating modes using optical pulses.
• To identify the optimal optical pulse energy required to induce mode switching.

Main Methods:

• Investigated the switching dynamics of semiconductor ring lasers.
• Performed experiments involving optical pulse injection.
• Analyzed system response and determined optimal pulse parameters.

Main Results:

• Characterized the response time for switching between unidirectional modes.
• Identified the optimal pulse energy for inducing mode switching in the bistable regime.
• Demonstrated the potential for controlled mode switching in semiconductor ring lasers.

Conclusions:

• Optical pulse injection provides a viable method for controlling mode switching in bistable semiconductor ring lasers.
• Understanding response time and optimal pulse energy is key for developing optical data storage devices based on these lasers.