Plasmonics is a field of study that explores the interaction of light waves and metallic surfaces, and the resulting density waves of electrons that can be generated from this interaction. The resulting electron density wave that propagates along the surface of the metal is referred to as a surface plasmon polariton, or a surface plasmon. Owing to the strong frequency dependence of the complex permittivity of the metal, plasmons themselves exhibit strong variations with frequency, and this frequency dependence results in surface plasmon resonances.
For nanophotonic structures that are comprised of periodic elements of different permittivity in one dimension (gratings) or two/three dimensions (photonic crystals), the periodic variation in the refractive index inhibits the propagation of electromagnetic waves of specific frequency, resulting in photonic band gaps corresponding to the band of frequencies over which radiation cannot propagate.
FDTD can be used to simulate light scattering in the presence of wavelength scale and sub-wavelength scale geometries. Since the scattering intensity is usually very weak compared to the illumination, a differential method is often used. The total field scattered field method (TFSF) is a convenient technique to get the scattered field, which can remove the mirror reflection.
Simulating the lithographic process prior to manufacture can help ensure that severe proximity effects do not compromise the manufacturing process. Ultimately, it is advantageous to employ semiconductor metrology techniques to ensure that the manufacturing process performed as expected. Advanced optical critical dimension metrology offers a means by which high-throughput wafer inspection can be used to identify surface defects and manufacturing (e.g. bridging) imperfections. Understanding the interplay of optical test conditions like polarization, incident angle, and wavelength and the specifics of the defect (size, orientation, etc) is a key capability of a rigorous optical simulation solution.
Liquid crystals are optical materials whose molecules can be oriented via the application of a static or low-frequency electric field. Given the anisotropic optical properties of these materials depending on their orientation, designers can use them to electrically tune the response of a wide class of photonic components including display and communications components including optical switches, couplers, shutters, modulators and beam steering devices. A rigorous Maxwell solver is required to predict the broadband response of photonic components incorporating liquid crystals and when the molecule orientation is varied over wavelength-scale distances.