Nanoscale Optics and Photonics Xiaodong Yang, October 25, 2011 Photonic crystals Surface plasmons Metamaterials The iridescence of Morpho butterfly Reference pictures resources: internet

The scale of things

The electromagnetic spectrum

Electronics and photonics roadmaps Vacuum tube Transistor Electronic integrated circuits Early electronics Nanofabrication and nanomanufacturing techniques Fast, low-cost, scalable and functional integrated devices The development of nanofabrication and nanomanufacturing techniques has not only permitted the success of electronic integrated circuits, but also has enabled the nanophotonic integrated circuits, for realizing fast, low-cost, scalable and functional integrated devices. Geometrical optics Optical MEMS Nanophotonic integrated circuits

Photonic crystals in nature Morpho butterfly Peacock feather Sea Mouse hair λ/2 Natural opals

Photonic crystals and defects Photonic crystal: periodically structured electromagnetic media, generally possessing photonic band gaps. Lattice constants are comparable to the wavelength of light in the material. Point defect: cavity λ/2 Line defect: waveguide

Photonic crystals with different dimensions

Surface Plasmons Gothic stained glass rose window of Notre-Dame de Paris

Water surface wave

Surface Plasmons at metal-dielectric interface λSP<<λ0 εd εm |Ez| Evanescent field Surface plasmons are EM waves propagating along metal-dielectric interface with collective electron oscillations. The interaction between light in dielectric and electron oscillations near the surface of metal generates surface plasmons. And SPs have strong light localization near the interface. Here is the dispersion relation. SP has wl much smaller than free space wl, due to the large k wave vector (lambda = 2 pi / k). Strong light localization near the metal-dielectric interface Surface Plasmons with large k SP wave interference 10 µm

Metamaterials: beyond natural materials “atoms” Atomic lattice constant a ~ 5.65 Å Optical wavelength λ ~1μm Homogeneous medium Crystal structure of sodium chloride (NaCl) λ a l Metamaterials Artificially fabricated structures Unit cell a << wavelength λ Effective-media theory can be applied Material properties not existing in natural materials “meta-atoms”

Negative Index of Refraction

Negative Index of Refraction Snell’s Law

Photonic integrated circuits Photonic crystals Surface plasmons Metamaterials

Applications of nanoscale optics and photonics Optical communications Photonic crystal fibers Photodetectors Optical switches Consumer electronics Semiconductor lasers CCD imaging LCD and LED displays Industrial applications Photolithography Laser manufacturing High-power fiber lasers Renewable energy Solar energy harvesting Thin-film photovoltaics LED lighting Nanoscale Optics and Photonics Biomedical Biosensors Fluorescence imaging Cancer therapy Optical nanostructures play important roles in many applications that drive our modern world. for example, optical communications including fiber, pd, optical switches; consumer electronics, industrial applications, biomedical, and renewable energy.