Effective nonlinear optical properties and optical bistability in composite media containing spherical particles with...

Area of Science:

• * Nonlinear optics
• * Materials science
• * Nanophotonics

Background:

• * Composite media with embedded nanospheres exhibit unique optical properties.
• * Understanding effective nonlinear optical properties is crucial for developing advanced optical devices.
• * Surface plasmon resonance in nanoparticles offers a pathway to enhance optical nonlinearities.

Purpose of the Study:

• * To investigate the effective nonlinear optical properties of composite media containing nonlinear nanospheres.
• * To explore the enhancement of optical nonlinear susceptibility near surface plasmon resonance.
• * To study optical bistability and tristability in such composite media under strong nonlinear conditions.

Main Methods:

• * Effective medium theory combined with linear Mie theory for weakly nonlinear cases.
• * Nonlinear Mie theory and self-consistent mean-field method for strong nonlinear cases.
• * Numerical simulations and comparison with quasistatic limit and Comsol simulations.

Main Results:

• * Significant enhancement of optical nonlinear susceptibility achieved at surface plasmon resonant wavelengths, tunable by nanoparticle size.
• * Optical bistability and tristability observed in the strong-nonlinear regime.
• * Bistable threshold fields demonstrated strong dependence on nanoparticle size and incident wavelength.

Conclusions:

• * Nonlinear nanocomposites exhibit large optical nonlinearity and tunable bistable behavior.
• * The findings support the potential application of these materials in nonlinear optical nanodevices.
• * Tunable optical properties make these composites promising for optical nanoswitches and nanomemories.