nano-optics 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. It is a branch of optics, optical engineering, electrical engineering, and nanotechnology. ...

, a plasmonic lens generally refers to a lens for

surface plasmon polariton Surface plasmon polaritons (SPPs) are electromagnetic waves that travel along a metal–dielectric or metal–air interface, practically in the infrared or visible-frequency. The term "surface plasmon polariton" explains that the wave involves bot ...

s (SPPs), i.e. a device that redirects SPPs to converge towards a single

focal point Focal point may refer to: * Focus (optics) * Focus (geometry) * Conjugate points, also called focal points * Focal point (game theory) * Unicom Focal Point, a portfolio management software tool * Focal point review, a human resources process for ...

. Because SPPs can have very small

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tro ...

, they can converge into a very small and very intense spot, much smaller than the

free space A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often dis ...

wavelength and the diffraction limit. A simple example of a plasmonic lens is a series of

concentric ring In geometry, two or more objects are said to be concentric, coaxal, or coaxial when they share the same center or axis. Circles, regular polygons and regular polyhedra, and spheres may be concentric to one another (sharing the same center point ...

s on a

metal film A resistor is a passivity (engineering), passive terminal (electronics), two-terminal electronic component, electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce c ...

. Any light that hits the film from free space at a 90 degree angle, known as the normal, will get coupled into a SPP (this part works like a diffraction grating coupler), and that SPP will be heading towards the center of the circles, which is the focal point. See als
Press release: Denser computer chips possible with plasmonic lenses
UC Berkeley News. 2008-10-22 Another example is a tapered "dimple". In 2007, a novel, or technologically new, plasmonic lenses and waveguide by modulating light a mesoscale dielectric structure on a metallic film with arrayed nano-slits, which have constant depth but variant widths. The slits transport electromagnetic energy in the form of SPPs in nano meter sized waveguides and provide desired phase adjustments for manipulating the

beam of light ''Beam of Light'' is the second full-length album by the Japanese rock band One Ok Rock, released on May 28, 2008. It reached No. 17 on the Oricon weekly chart, and charted for six weeks before it dropped out. Track listing Notes * "Abducti ...

. The scientists claim that it is an improvement over other

subwavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tro ...

imaging techniques, such as " superlenses", where the object and image are confined to the near field. These devices have been suggested for various applications that take advantage of the small size and high intensity of the SPPs at the focal point. These include

photolithography In integrated circuit manufacturing, photolithography or optical lithography is a general term used for techniques that use light to produce minutely patterned thin films of suitable materials over a substrate, such as a silicon wafer, to protect ...

, heat-assisted magnetic recording,

microscopy Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...

, biophotonics, biological molecule sensors, and

solar cells A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physics, physical and Chemical substance, chemical phenomenon. These often come up in discussions of superlenses.

References

Further reading