View source for Bubblegram

{{Short description|Solid block of glass or plastic exposed to lasers to generate 3-D designs inside}}
{{Distinguish|Vitreography|Vitrigraph (disambiguation)}}
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[[File:Laser glass sculpture caffeine molecule.jpg|thumb|A laser glass sculpture of a [[caffeine]] molecule]]

A '''bubblegram''' (also known as '''laser crystal''', '''Subsurface Laser Engraving''', '''3D crystal engraving''' or '''vitrography''') is a solid block of [[glass]] or transparent [[plastic]] that has been exposed to [[laser]] beams to generate [[three-dimensional space|three-dimensional]] designs inside. The image is composed of many small points of [[fracture]] or other visible deformations and appears to float inside the block.

==Description==
Each point is created by a laser beam focused to high intensity at that location by a computer-controlled opto-mechanical system. A complex or highly detailed image occupying a 5 cm (2 inch) cubic volume typically requires the creation of tens of thousands of such points.<ref>[https://web.archive.org/web/20001021052517/http://www.spie.org/web/oer/november/nov99/lasedamage.html "Laser-induced damage creates interior images"], ''OE Reports'', Number 191, November 1999 (via Internet Archive Wayback Machine). Retrieved 2013-02-16.</ref>

Bubblegram images may be created by intersecting laser beams in appropriately [[dopant|doped]] plastic to induce a [[chemical reaction]] via heat or [[photonic]] excitation, creating bubbles or nodes where the plastic has a different [[index of refraction]].

Glass block bubblegrams of Russian origin entered international commerce as a novelty in the late 1990s, but high prices and the predominantly simple, inartistic subject matter severely limited market penetration. In the early 2000s, a much less expensive, more visually appealing and highly diverse array of Chinese-made bubblegram novelties achieved wide commercial success in the United States, to the extent of becoming a [[fad]]: representations of monuments, corporate symbols, religious imagery, mythical creatures and nature scenes appeared in gift shops.

There also exist companies which will take custom photographs of people, convert them to a [[heightmap]], then render that as a bubblegram [[Souvenir|memento]].

==See also==
* [[Laser engraving]]
* [[Volumetric printing]]

==References==
{{Reflist}}

==External links==
* ''[http://www.bathsheba.com/crystal/process Laser Crystal Technique]'' How a single conical laser beam makes a bubblegram

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[[Category:3D imaging]]
[[Category:Glass art]]
[[Category:Laser applications]]