Breakthrough anti-reflection coating could mean advances in optics, LED lighting and lenses

Saturday, March 24, 2007 by: Christian Evans
Tags: optics, health news, Natural News

A team of researchers from Rensselaer Polytechnic Institute has created a new optical coating that enables greater control over the basic properties of light. The world's first material that reflects virtually no light can eliminate unwanted reflections, and has been an active technological goal of scientists for years.

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What you need to know - Conventional View

• Most surfaces, from a puddle of water to a mirror, reflect some light.

• One type of optical coating is an anti-reflection coating, which reduces unwanted reflections from surfaces, and is commonly used on spectacles and photographic lenses.

• Conventional anti-reflection coatings, although widely used, work only at a single wavelength and only when the light source is positioned directly perpendicular to the material.

• A technique called oblique angle deposition strongly reduces or eliminates reflection at all wavelengths and incoming angles of light.

• The oblique angle evaporation technique is already widely used in the industry, and the design can be applied to any type of substrate -- not just an expensive semiconductor such as aluminum nitride.

• This is material with a refractive index of 1.05, which is extremely close to the refractive index of air and the lowest ever reported. Window glass, in comparison, has a refractive index of about 1.45.

• The refractive index is a fundamental property that governs the amount of light a material reflects, as well as other optical properties such as diffraction, refraction, and the speed of light inside the material.

• The new optical coating could find use in just about any application where light travels into or out of a material, such as more efficient solar cells, brighter LEDs, "smart" lighting, high-reflectance mirrors, and black body radiation.

Bottom line

• A new optical light technology reflects virtually no light.