{"id":4950,"date":"2010-08-13T08:52:02","date_gmt":"2010-08-13T08:52:02","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/2010\/08\/13\/do-not-look-in-laser-pointer-w\/"},"modified":"2010-08-13T08:52:02","modified_gmt":"2010-08-13T08:52:02","slug":"do-not-look-in-laser-pointer-w","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2010\/08\/13\/do-not-look-in-laser-pointer-w\/","title":{"rendered":"Do Not Look In Laser Pointer With Remaining Eye"},"content":{"rendered":"<p>Some folks I used to work with at NIST have looked at cheap green laser pointers, and <a href=\"http:\/\/www.nist.gov\/physlab\/div841\/laser_080310.cfm\">found a potential danger<\/a>. Some of the dimmer-looking green lasers are not so dim in the infrared, and in one case emitted 10X the rated power in invisible light. This could be a potential eye hazard.<\/p>\n<p>You can read their <a href=\"http:\/\/arxiv.org\/abs\/1008.1452\">full report on the arxiv<\/a>. It&#8217;s got a nice description of how green laser pointers turn infrared light into visible light, which is really pretty awesome&#8211; a guy I met at a conference once declared them the coolest invention ever, because it&#8217;s &#8220;quantum optics in the palm of your hand.&#8221; Better yet, it describes a cheap and easy experiment you can do to see if your green laser pointer is dangerous, using a CD and a webcam. And best of all, it demonstrates a clear understanding of what these are really used for:<\/p>\n<blockquote>\n<p>Note that the infrared spots [in a diffraction pattern] exhibit greater divergence than the green.  The infrared light  spreads out beyond the green, which could be injurious, for example, to a cat closely chasing a spot of green light.<\/p>\n<\/blockquote>\n<p>So, if your green laser doesn&#8217;t have the oomph you would like it to have, it might be because you&#8217;re looking at the wrong wavelength. So avoid shining it into your cat&#8217;s eyes until you get a chance to do their experiment and check it out.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Some folks I used to work with at NIST have looked at cheap green laser pointers, and found a potential danger. Some of the dimmer-looking green lasers are not so dim in the infrared, and in one case emitted 10X the rated power in invisible light. This could be a potential eye hazard. You can&hellip; <a class=\"more-link\" href=\"http:\/\/chadorzel.com\/principles\/2010\/08\/13\/do-not-look-in-laser-pointer-w\/\">Continue reading <span class=\"screen-reader-text\">Do Not Look In Laser Pointer With Remaining Eye<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"1","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,169,238,7,23,11],"tags":[],"class_list":["post-4950","post","type-post","status-publish","format-standard","hentry","category-experiment","category-lasers","category-optics","category-physics","category-quantum_optics","category-science","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/4950","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/comments?post=4950"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/4950\/revisions"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=4950"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=4950"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=4950"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}