Cross-Kerr effect in a parity-time symmetric optomechanical system

Area of Science:

• Optomechanics
• Quantum Optics
• Nonlinear Optics

Background:

• Parity-time (PT) symmetric systems offer unique control over light-matter interactions.
• Optomechanical systems couple optical fields to mechanical resonators, enabling sensitive measurements and novel quantum phenomena.
• Cross-Kerr effects introduce nonlinear interactions between optical modes and mechanical elements.

Purpose of the Study:

• Investigate the influence of cross-Kerr effects on optomechanically induced transparency (OMIT) in PT-symmetric optomechanical systems.
• Analyze spectral features and switching behaviors under different coupling regimes.
• Demonstrate the potential for tunable absorption-to-amplification conversion.

Main Methods:

• Theoretical investigation of a parity-time symmetric optomechanical system.
• Analysis of the asymmetric optomechanically induced transparency (OMIT) spectrum.
• Derivation of analytic findings to explain spectral features.
• Simulation of spectral evolution under varying tunnel coupling strengths.

Main Results:

• In the double-passive case, an asymmetric OMIT spectrum with a broad absorption peak and a Kerr-interaction-dependent absorption line was observed.
• In the passive-active case, resonance peaks increased with weak tunnel coupling, contrasting the double-passive scenario.
• Strong tunnel coupling transformed absorption peaks into amplification, with the central dip splitting due to normal mode splitting.

Conclusions:

• Cross-Kerr coupling in PT-symmetric optomechanical systems induces distinctive asymmetric OMIT spectra.
• The system exhibits tunable spectral properties, allowing a switch from absorption to amplification by adjusting tunnel interaction.
• These findings offer possibilities for novel optical devices with controllable gain and absorption characteristics.