Full-color printing with a resolution of 100,000 DPI on the diffraction limit
Scientists from the Singapore Science, Technology and Research Agency (A * STAR) implemented a method of printing microscopic images with a resolution of about 100,000 DPI. It is assumed that this method will be used for printing watermarks, secret messages, in cryptography and information storage systems.
The diffraction limit is the minimum point size that can be distinguished in reflected light. It is equal to about half the wavelength, after which the neighboring pixels begin to visually merge with each other. In the middle of the visible spectrum, the wavelength is about 500 nm, so that the pixels must be located at a distance of more than 250 nm from each other, so that they can be seen in an optical microscope. Here is exactly the print resolution implemented.
Lena's image measuring 50 × 50 micrometers
Each colored dot is an array of nanostables coated with gold and silver nanodisks.
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Due to the effect of plasmon resonance , the structure is able to resonate with electromagnetic radiation at different frequencies. Depending on the distance between the columns, the length of the reflected wave changes, which the eye perceives as a specific color.
Scientists have found a way to "generate" waves for any color in the range from red to blue. On the sample with Lena, the left photo was taken under a microscope before the application of metal nanodiscs, and the right photo after.
People with maximum vision are able to notice an object of no more than 20-30 micrometers in size, and this object will look like a dot, so a 50 × 50 full-color picture cannot be seen with a naked eye.
Of the advantages of the new method is the durability of the metallic coating. Among the shortcomings is the high cost and too long a printing process, which limits the image area.
The diffraction limit is the minimum point size that can be distinguished in reflected light. It is equal to about half the wavelength, after which the neighboring pixels begin to visually merge with each other. In the middle of the visible spectrum, the wavelength is about 500 nm, so that the pixels must be located at a distance of more than 250 nm from each other, so that they can be seen in an optical microscope. Here is exactly the print resolution implemented.
Lena's image measuring 50 × 50 micrometers
Each colored dot is an array of nanostables coated with gold and silver nanodisks.
')
Due to the effect of plasmon resonance , the structure is able to resonate with electromagnetic radiation at different frequencies. Depending on the distance between the columns, the length of the reflected wave changes, which the eye perceives as a specific color.
Scientists have found a way to "generate" waves for any color in the range from red to blue. On the sample with Lena, the left photo was taken under a microscope before the application of metal nanodiscs, and the right photo after.
People with maximum vision are able to notice an object of no more than 20-30 micrometers in size, and this object will look like a dot, so a 50 × 50 full-color picture cannot be seen with a naked eye.
Of the advantages of the new method is the durability of the metallic coating. Among the shortcomings is the high cost and too long a printing process, which limits the image area.
Source: https://habr.com/ru/post/149489/
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