UV laser creates disappearing ink in normal printer paper

2019-08-05

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Ordinary printer paper is darkened by a high power UV laser, and then the affected area disappears in four minutes! This is caused by fluorescent brightening agents that are added to printer paper, which are temporarily overloaded by the intense UV light. It seems that oxygen plays a role in this, as hydrogen peroxide applied to the marks cause them to disappear instantly, and prevent them from being formed again by the laser. Performing the experiment in argon appears to slow the disappearing ink effect.

https://en.wikipedia.org/wiki/(E)-Stilbene

http://abchemitrans.com/dokumenty/Brochure_OPTICAL_BRIGHTENERS.pdf

https://www.tandfonline.com/doi/abs/10.1080/19440049.2014.934302?mobileUi=0&journalCode=tfac20

https://patents.google.com/patent/US20140339462A1

https://www.patreon.com/AppliedScience