Nonlinear dynamics of a quantum cascade laser with optical injection

Area of Science:

• Quantum optics
• Semiconductor lasers
• Nonlinear dynamics

Background:

• Quantum cascade lasers (QCLs) are crucial semiconductor devices for mid-infrared applications.
• Understanding their nonlinear dynamics under external perturbations like optical injection is vital for device optimization.
• Previous studies have explored QCL dynamics, but comprehensive analysis of injection-locking regimes remains an active research area.

Purpose of the Study:

• To investigate the nonlinear dynamics of a quantum cascade laser subjected to optical injection.
• To characterize the optical power behavior, including hysteresis, within different locking regimes.
• To identify and analyze distinct dynamical states such as periodic oscillations and spiking pulsations.

Main Methods:

• Numerical simulations of the QCL rate equations.
• Analysis of optical power as a function of detuning frequency under varying pump currents.
• Bifurcation analysis to map out different dynamical regimes.

Main Results:

• A clear hysteresis behavior in optical power was observed within the stable locking regime as a function of detuning frequency.
• Outside the stable locking regime, the QCL predominantly exhibited periodic oscillations.
• At high pump currents and near the negative locking boundary, the laser demonstrated spiking pulsations with uniform amplitude.

Conclusions:

• The nonlinear dynamics of QCLs under optical injection are complex and exhibit rich phenomena.
• Hysteresis, periodic oscillations, and spiking pulsations are key dynamical states dependent on injection parameters and pump current.
• These findings provide valuable insights for controlling and designing QCLs for specific applications.