New technology that can read pages of a closed book
By: Team Ifairer | Posted: 12-09-2016
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The difference in refractive index - the degree to which they bend light - between the air and the paper means that the boundary between the two will reflect terahertz radiation back to a detector.
In the new system, a standard terahertz camera emits ultrashort bursts of radiation, and the camera's built-in sensor detects their reflections.
From the reflections' time of arrival, the algorithm can gauge the distance to the individual pages of the book.