{"id":466632,"date":"2021-02-04T11:38:20","date_gmt":"2021-02-04T16:38:20","guid":{"rendered":"http:\/\/www.rochester.edu\/newscenter\/?p=466632"},"modified":"2023-02-15T14:44:15","modified_gmt":"2023-02-15T19:44:15","slug":"froc-optical-coatings-reflects-and-transmits-color-466632","status":"publish","type":"post","link":"https:\/\/www.rochester.edu\/newscenter\/froc-optical-coatings-reflects-and-transmits-color-466632\/","title":{"rendered":"An optical coating like no other"},"content":{"rendered":"
A \u2018FROC\u2019 can both transmit and reflect the same color simultaneously, a breakthrough in optical coating.<\/div>\n
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For more than a century, optical coatings have been used to better reflect certain wavelengths of light from lenses and other devices or, conversely, to better transmit certain wavelengths through them. For example, the coatings on tinted eyeglasses reflect, or \u201cblock out,\u201d harmful blue light and ultraviolet rays.<\/p>\n

But until now, no optical coating had ever been developed that could simultaneously reflect and transmit the same wavelength, or color.<\/p>\n

In a paper<\/a> in Nature Nanotechnology<\/em>, researchers at the University of Rochester<\/a> and Case Western Reserve University describe a new class of optical coatings, so-called Fano Resonance Optical Coatings (FROCs), that can be used on filters to reflect and transmit colors of remarkable purity.<\/p>\n

In addition, the coating can be made to fully reflect only a very narrow wavelength range.<\/p>\n

\u201cThe narrowness of the reflected light is important because we want to have a very precise control of the wavelength,\u201d says corresponding author Chunlei Guo<\/a>, professor at Rochester\u2019s Institute of Optics<\/a>. \u201cBefore our technology, the only coating that could do this was a multilayered dielectric mirror, that is much thicker, suffers from a strong angular dependence, and far more expensive to make. Thus, our coating can be a low-cost and high-performance alternative.\u201d<\/p>\n