Configurational disorder and the local field effects in nonlinear optical systems

Area of Science:

• Nonlinear Optics
• Condensed Matter Physics
• Quantum Optics

Background:

• The Clausius-Mossoti equation is a standard model for relating macroscopic properties to microscopic polarizabilities.
• Disordered systems, such as atoms in crystals or amorphous hosts, exhibit local field fluctuations not accounted for in the standard model.
• Understanding these fluctuations is crucial for accurate modeling of optical properties.

Purpose of the Study:

• To extend the Clausius-Mossoti limit to include local field fluctuations in disordered nonlinear optical systems.
• To analyze the impact of configurational disorder on atom susceptibility.
• To investigate the implications for quantum coherence phenomena like lasing without inversion.

Main Methods:

• Development of a random local mean field approach.
• Neglect of correlations between dipole moments of different atoms.
• Application of the formalism to 3-level quantum systems with coherence.

Main Results:

• Configurational fluctuations significantly alter local electric fields experienced by atoms.
• Atom susceptibility is suppressed compared to predictions from the standard Clausius-Mossoti equation.
• The developed model accurately describes systems with an absorptionless index of refraction and lasing without inversion.

Conclusions:

• The Clausius-Mossoti limit is insufficient for disordered nonlinear optical systems.
• Local field fluctuations induced by atomic disorder must be considered for precise optical property predictions.
• This work provides a more accurate theoretical framework for understanding quantum coherence in disordered media.