Extending the FDTD GVADE method nonlinear polarization vector to include anisotropy

Area of Science:

• Nonlinear optics
• Computational electromagnetics

Background:

• The finite-difference time-domain general vector auxiliary differential equation method is a key numerical technique.
• Modeling nonlinear polarization in isotropic media is crucial for understanding light-matter interactions at optical frequencies.

Purpose of the Study:

• To extend the existing numerical method to incorporate anisotropy in nonlinear isotropic media.
• To investigate the impact of anisotropic nonlinear polarization on optical phenomena.

Main Methods:

• Extension of the finite-difference time-domain general vector auxiliary differential equation method to 3D Cartesian coordinates.
• Inclusion of the anisotropic nonlinear polarization vector in simulations.
• Development of 2D transverse magnetic simulations for specific materials.

Main Results:

• The extended method successfully incorporates anisotropic nonlinear polarization.
• Simulations in fused silica demonstrated differences between isotropic and anisotropic polarization models.
• Carbon disulfide simulations highlighted molecular re-orientation-induced polarization anisotropy.

Conclusions:

• The enhanced numerical method provides a more accurate representation of nonlinear optical phenomena in anisotropic media.
• The findings are significant for precise optical device design and material characterization.