June 28, 2006

More on Metamaterials and Superlens over 5 times better than ordinary lenses

Superlens focus is 5 to 10 (1/20th of wavelength) times better than the diffraction limit (half of wavelength). For light that is 350 nanometers it could focus to 17 nanometers. Applications: far faster computers, communications, microscopes, telescopes, DVDs etc... The goal is a perfect lens. Metamaterials make this and invisibility possible.

Powerpoint tutorial, by G Shvets of the Univeristy of Texas at Austin, on meta-materials and applying superlenses to laser plasma accelerators The powerpoint discusses plans to use superlenses to focus down to 1/20th of a wavelength. Half of wavelength is the diffraction limit for a conventional lens. Lenses that are 10 times better are planned and lenses 5 times better have been achieved.

Researchers at the University of Texas at Austin and at Case Western Reserve University in Cleveland have created a functional superlens in the mid-infrared, achieving a resolution of better than λ/10 using an 11-µm source. According to the group’s calculations, a square array of nanorods, perhaps fabricated of anodized aluminum, may demonstrate superlensing at near-IR and visible wavelengths.

The scientists are investigating the use of a square array of metallic nanorods spaced approximately 100 nm apart. This will produce a metamaterial with a negative refractive index and numerical calculations show that such a structure will exhibit superlensing.

Here is some of work with gold nanorods which show the negative index effect. However, the nanorods are too large and too much light is absorbed.

Applications are any technology where sub-wavelengths would provide performance benefits. Various optical related electronics can get smaller. It could be used for photo-nanolithography. (nanolithography is discussed here at wikipedia and photolithography is discussed at wikipedia. Combining them with photo-nanolithography means cheaper ways to make more powerful computer chips) Photo-nanolithography would make it possible to etch smaller electronic devices and circuits, resulting in more powerful computers, as well as new types of antennas, computer components and consumer electronics such as cell phones that use light instead of electricity for carrying signals and processing information, resulting in faster communications.

Previously discussed possibilities include invisibility, supertelescopes, supermicroscopes and many more.

Related article:
Soft x-rays have been focused to 15 nanometers and 6 nanometers is possible

Metamaterials background and potential applications

This study develops a general recipe for the design of media that create perfect invisibility within the accuracy of geometrical optics. The method developed here can also be applied to escape detection by other electromagnetic waves or sound.

Controlling electromagnetic fields with metamaterials