Editing Yellow (section)

==== Lasers ====
[[Laser]]s emitting in the yellow part of the spectrum are less common and more expensive than most other colors.<ref name="laserglow">{{cite web |url=http://www.laserglow.com/index.php?portable |title=Laserglow – Blue, Red, Yellow, Green Lasers |publisher=Laserglow.com |access-date=27 March 2009 |quote=described as an "extremely rare yellow". |archive-date=24 March 2009 |archive-url=https://web.archive.org/web/20090324123802/http://www.laserglow.com/index.php?portable |url-status=live }}</ref> In commercial products diode pumped solid state ([[Diode-pumped solid-state laser|DPSS]]) technology is employed to create the yellow light. An infrared laser diode at 808&nbsp;nm is used to pump a crystal of neodymium-doped yttrium vanadium oxide (Nd:YVO4) or neodymium-doped yttrium aluminum garnet (Nd:YAG) and induces it to emit at two frequencies (281.76&nbsp;THz and 223.39&nbsp;THz: 1064&nbsp;nm and 1342&nbsp;nm wavelengths) simultaneously. This deeper infrared light is then passed through another crystal containing potassium, titanium and phosphorus (KTP), whose non-linear properties generate light at a frequency that is the sum of the two incident beams (505.15&nbsp;THz); in this case corresponding to the wavelength of 593.5&nbsp;nm ("yellow").<ref name="ledmuseum">{{cite web |url=http://ledmuseum.candlepower.us/yelldpss.htm |title=Yellow (593.5&nbsp;nm) DPSS Laser Module |last=Johnson |first=Craig |date=22 March 2009 |publisher=The LED Museum |access-date=27 March 2009 |archive-date=16 February 2009 |archive-url=https://web.archive.org/web/20090216143902/http://ledmuseum.candlepower.us/yelldpss.htm |url-status=live }}</ref> This wavelength is also available, though even more rarely, from a [[helium–neon laser]]. However, this not a true yellow, as it exceeds 590&nbsp;nm. A variant of this same DPSS technology using slightly different starting frequencies was made available in 2010, producing a wavelength of 589&nbsp;nm, which is considered a true yellow color.<ref name="laserglow2">{{cite web |url=http://www.laserglow.com/GRH |title=Laserglow – Blue, Red, Yellow, Green Lasers |publisher=Laserglow.com |access-date=12 August 2011 |archive-date=5 August 2011 |archive-url=https://web.archive.org/web/20110805054301/https://www.laserglow.com/GRH |url-status=live }}</ref> The use of yellow lasers at 589&nbsp;nm and 594&nbsp;nm have recently become more widespread thanks to the field of [[optogenetics]].<ref name="laserglow3">{{cite web |url=http://www.laserglow.com/page/optogenetics |title=Laserglow – Blue, Red, Yellow, Green Lasers |publisher=Laserglow.com |access-date=20 September 2011 |archive-date=15 September 2011 |archive-url=https://web.archive.org/web/20110915023159/http://www.laserglow.com/page/optogenetics |url-status=live }}</ref>