Holograms: Difference between revisions
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==How does it work?== | ==How does it work?== | ||
To create a hologram, holography uses the wave nature of light. In a normal photograph, lenses are used to focus an image on film or an electronic chip, recording where there is light or not. With the holographic technique, the shape a light wave takes after it bounces off an object is recorded. It uses interfering waves of light to capture images that can be 3D. When waves of light meet they interfere with each other, analogous to what happens with waves of water. The pattern created by the interference of waves | To create a hologram, holography uses the wave nature of light. In a normal photograph, lenses are used to focus an image on film or an electronic chip, recording where there is light or not. With the holographic technique, the shape a light wave takes after it bounces off an object is recorded. It uses interfering waves of light to capture images that can be 3D. When waves of light meet they interfere with each other, analogous to what happens with waves of water. The pattern created by the interference of waves contains the information used to make the holograms <ref name=”8”> Holographic Studios. A brief history of holography. Retrieved from http://www.holographer.com/history-of-holography/</ref>. | ||
True 3D holograms could not be a practical reality without the invention of the laser. A laser creates waves of light that are coherent. It is this coherent light that makes it possible to record the light wave interference patterns of holography <ref name=”8”></ref>. While white light contains all of the different frequencies of light traveling in all directions, laser light produces light that has only one wavelength and one color (Figure 1) <ref name=”7”></ref>. | True 3D holograms could not be a practical reality without the invention of the laser. A laser creates waves of light that are coherent. It is this coherent light that makes it possible to record the light wave interference patterns of holography <ref name=”8”></ref>. While white light contains all of the different frequencies of light traveling in all directions, laser light produces light that has only one wavelength and one color (Figure 1) <ref name=”7”></ref>. | ||
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==Brief history== | ==Brief history== | ||
'''1886 -''' Gabriel Lippmann, in France, develops a theory of using light wave interference to capture color in photography. He presented | '''1886 -''' Gabriel Lippmann, in France, develops a theory of using light wave interference to capture color in photography. He presented his theory in 1891 to the Academy of Sciences, along with some primitive examples of his interference color photographs. In 1983, he presented perfect color photographs to the Academy and won a Nobel Prize in Physics in 1908 due to his work in this area. | ||
1947 - Dennis Gabor develops the theory of holography. He coined the term hologram from the Greek words holos (meaning ‘whole’) and gramma (‘message’). | 1947 - Dennis Gabor develops the theory of holography. He coined the term hologram from the Greek words holos (meaning ‘whole’) and gramma (‘message’). | ||