![]() Heat-assisted magnetic recording is a nanophotonic approach to increasing the amount of data that a magnetic disk drive can store. Plasmonic techniques have also been proposed for this application. Using various techniques such as immersion lithography and phase-shifting photomasks, it has indeed been possible to make images much finer than the wavelength-for example, drawing 30 nm lines using 193 nm light. In order to make very small transistors, the light needs to be focused into extremely sharp images. Integrated circuits are made using photolithography, i.e. An example is spasers, the surface plasmon version of lasers. Very small lasers require subwavelength optical cavities. Small lasers have various desirable properties for optical communication including low threshold current (which helps power efficiency) and fast modulation (which means more data transmission). Small photodetectors tend to have a variety of desirable properties including low noise, high speed, and low voltage and power. If light can be squeezed into a small volume, it can be absorbed and detected by a small detector. ![]() A few of these goals are summarized below. Nanophotonics researchers pursue a very wide variety of goals, in fields ranging from biochemistry to electrical engineering to carbon-free energy. Nevertheless, it is possible to squeeze light into a nanometer scale using other techniques like, for example, surface plasmons, localized surface plasmons around nanoscale metal objects, and the nanoscale apertures and nanoscale sharp tips used in near-field scanning optical microscopy (SNOM or NSOM) and photoassisted scanning tunnelling microscopy. Normal optical components, like lenses and microscopes, generally cannot normally focus light to nanometer (deep subwavelength) scales, because of the diffraction limit ( Rayleigh criterion). The term "nano-optics", just like the term "optics", usually refers to situations involving ultraviolet, visible, and near-infrared light (free-space wavelengths from 300 to 1200 nanometers). It often involves dielectric structures such as nanoantennas, or metallic components, which can transport and focus light via surface plasmon polaritons. ![]() It is a branch of optics, optical engineering, electrical engineering, and nanotechnology. Nanophotonics or nano-optics is the study of the behavior of light on the nanometer scale, and of the interaction of nanometer-scale objects with light. ![]()
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