PT-symmetric phonon laser under gain saturation effect

Area of Science:

• Quantum optics
• Solid-state physics
• Nanophotonics

Background:

• Phonon lasers, analogous to optical lasers, offer potential applications in diverse scientific fields.
• The study focuses on a specific phonon laser implementation using two coupled micro-cavities, with one containing an optical gain medium.

Purpose of the Study:

• Investigate the dynamics and operational parameters of a phonon laser system.
• Explore the effects of optical gain saturation and nonlinearity on stimulated phonon emission.
• Determine conditions for achieving workable phonon laser operation with a low threshold.

Main Methods:

• Utilized a composite numerical approach alongside a dynamical approach to analyze system time evolution.
• Investigated the system under a blue-detuned external drive, inducing dynamical instability.
• Considered the saturation of the optical gain medium to model nonlinear effects.

Main Results:

• Demonstrated that phonon laser operation is achievable by carefully selecting system parameters.
• Identified that optical gain saturation leads to complex behaviors in stimulated phonon emission.
• Found that suitable coupling between micro-cavities and optimal damping rates can lower the phonon laser threshold.

Conclusions:

• Phonon laser operation is feasible in the studied coupled micro-cavity system.
• Parameter optimization, including cavity coupling and damping, is crucial for achieving low-threshold phonon lasing.
• The findings provide insights into controlling and enhancing phonon laser performance for potential applications.