What if? digital cameras or smartphones without the bulky lenses or eyeglasses with lenses that are paper thin.
Researchers have always thought that flat, ultra thin optical lenses for cameras or other devices were impossible because of the way all the colors of light must bend through them. Consequently, photographers have had to put up with more cumbersome and heavier curved lenses. But University of Utah electrical and computer engineering professor Rajesh Menon and his team have developed a new method of creating optics that are flat and thin yet can still perform the function of bending light to a single point, the basic step in producing an image.
Instead of the lens having a curvature, it can be very flat so you get completely new design opportunities for imaging systems like the ones in your mobile phone," Menon says. "Our results correct a widespread misconception that flat, diffract lenses cannot be corrected for all colors simultaneously.
In order to capture a photographic image in a camera or for your eyes to focus on an image through eyeglasses, the different colors of light must pass through the lenses and converge to a point on the camera sensor or on the eye's retina. How light bends through curved lenses is based on the centuries-old concept known as refraction, a principle that is similar to when you put a pencil in a glass of water and notice that it "bends" in the water. To do this, cameras typically will use a stack of multiple curved lenses in order to focus all of the colors of light to a single point. Multiple lenses are needed because different colors bend differently, and they are designed to ensure that all colors come to the same focus.
Menon and his team discovered a way to design a flat lens that can be 10 times thinner than the width of a human hair or millions of times thinner than a camera lens today. They do it through a principle known as diffraction in which light interacts with micro structures in the lens and bends.
Researchers have always thought that flat, ultra thin optical lenses for cameras or other devices were impossible because of the way all the colors of light must bend through them. Consequently, photographers have had to put up with more cumbersome and heavier curved lenses. But University of Utah electrical and computer engineering professor Rajesh Menon and his team have developed a new method of creating optics that are flat and thin yet can still perform the function of bending light to a single point, the basic step in producing an image.
Instead of the lens having a curvature, it can be very flat so you get completely new design opportunities for imaging systems like the ones in your mobile phone," Menon says. "Our results correct a widespread misconception that flat, diffract lenses cannot be corrected for all colors simultaneously.
In order to capture a photographic image in a camera or for your eyes to focus on an image through eyeglasses, the different colors of light must pass through the lenses and converge to a point on the camera sensor or on the eye's retina. How light bends through curved lenses is based on the centuries-old concept known as refraction, a principle that is similar to when you put a pencil in a glass of water and notice that it "bends" in the water. To do this, cameras typically will use a stack of multiple curved lenses in order to focus all of the colors of light to a single point. Multiple lenses are needed because different colors bend differently, and they are designed to ensure that all colors come to the same focus.
Menon and his team discovered a way to design a flat lens that can be 10 times thinner than the width of a human hair or millions of times thinner than a camera lens today. They do it through a principle known as diffraction in which light interacts with micro structures in the lens and bends.
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