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We exploit theoretically nonlinear optical materials by graded multilayered colloidal crystals, whose basic layer is made of metallodielectric nanoparticles immersed periodically in a host fluid. In the crystals, either the volume fraction of nanoparticles or the dielectric constant of host fluid can vary gradually within layers. The electric field distribution can be shown to exhibit a peak in a certain layer, and that the position of the peak can change by tuning the incident angular frequency. Such a gradation-controlled electric field distribution serves as a physical mechanism for understanding the enhanced nonlinear optical responses with a broad plasmon band. [ABSTRACT FROM AUTHOR]

The authors theoretically exploit a class of nonlinear optical materials, which are made of single domain ferromagnetic nanoparticles coated by a nonmagnetic nanoshell with an intrinsic second-harmonic generation (SHG) susceptibility in a nonmagnetic host fluid. The SHG of such materials possess magnetic-field controllabilities, i.e., magnetic-field-controllable anisotropy, redshift, and enhancement, which are caused to appear by the shift of a resonant plasmon frequency due to the formation of the chains of the coated nanoparticles. [ABSTRACT FROM AUTHOR]

We theoretically exploit a class of colloidal-crystal-based nonlinear optical materials, which are made of graded metallodielectric nanoparticles suspended in a host fluid. Such materials can have both an enhancement and a redshift of optical nonlinearity, due to the gradation inside the nanoparticles as well as the lattice effects arising from the periodic structure. [ABSTRACT FROM AUTHOR]

We theoretically explore a type of bifunctional cloak possessing both electrical and thermal cloaking functionality. We employ a composite material to design the cloak shell. By using effective medium theory, the effective electrical and thermal conductivities of the composite material should meet the perfect conductivity profile calculated from the coordinate transformation approach. In the design, we choose nonspherical nanoparticles with appropriate electrical and thermal conductivities, shape aspects, and volume fractions. Furthermore, finite element simulations are performed to verify the properties of such bifunctional cloaks. [ABSTRACT FROM AUTHOR]

We theoretically exploit a class of one-dimensional double-layer photonic crystals based on colloidal ferrofluids, which are made of ferromagnetic nanoparticles suspended in a carrier liquid. Depending on the magnetic-field-induced anisotropic property of the ferrofluid, precise controllability of the band gaps is demonstrated to be possible by applying an appropriate external magnetic field. [ABSTRACT FROM AUTHOR]