NIST Researchers Develop Nanoscale Devices That Respond to the Angle of Incident LightImagine a mini
NIST Researchers Develop Nanoscale Devices That Respond to the Angle of Incident LightImagine a miniature device that suffuses each room in your house with a different hue of the rainbow—purple for the living room, perhaps, blue for the bedroom, green for the kitchen. A team led by scientists at the National Institute of Standards and Technology (NIST) has, for the first time, developed nanoscale devices that divide incident white light into its component colors based on the direction of illumination, or directs these colors to a predetermined set of output angles.Viewed from afar, the device, referred to as a directional color filter, resembles a diffraction grating, a flat metal surface containing parallel grooves or slits that split light into different colors. However, unlike a grating, the nanometer-scale grooves etched into the opaque metal film are not periodic—not equally spaced. They are either a set of grooved lines or concentric circles that vary in spacing, much smaller than the wavelength of visible light. These properties shrink the size of the filter and allow it to perform many more functions than a grating can.For instance, the device’s nonuniform, or aperiodic, grid can be tailored to send a particular wavelength of light to any desired location. The filter has several promising applications, including generating closely spaced red, green and blue color pixels for displays, harvesting solar energy, sensing the direction of incoming light and measuring the thickness of ultrathin coatings placed atop the filter.Read more. -- source link
#materials science#science#nanotechnology#filters