Editing Q-switching (section)

==Applications==
Q-switched lasers are often used in applications which demand high laser [[intensity (physics)|intensities]] in nanosecond pulses, such as metal cutting or pulsed [[holography]]. [[Nonlinear optics]] often takes advantage of the high peak powers of these lasers, offering applications such as [[3D optical data storage]] and [[3D microfabrication]]. However, Q-switched lasers can also be used for measurement purposes, such as for distance measurements ([[range finding]]) by measuring the time it takes for the pulse to get to some target and the reflected light to get back to the sender. It can be also used in [[chemical dynamic]] study, e.g. [[temperature jump]] [[relaxation (physics)|relaxation]] study.<ref>
{{cite journal
|author1=Reiner, J. E. |author2=Robertson, J. W. F. |author3=Burden, D. L. |author4=Burden, L. K. |author5=Balijepalli, A. |author6=Kasianowicz, J. J. |year = 2013
|title = Temperature Sculpting in Yoctoliter Volumes
|journal = Journal of the American Chemical Society
|volume = 135|issue=8 |pages = 3087–3094
|issn = 0002-7863
|pmid = 23347384|doi = 10.1021/ja309892e
|pmc=3892765
|bibcode=2013JAChS.135.3087R }}
</ref>

{{external media | width = 210px | float = right | headerimage= [[File:Old (8497164706).jpg|210px]] | audio1 = [https://www.sciencehistory.org/distillations/podcast/rethinking-ink “Rethinking Ink”], ''Distillations'' Podcast Episode 220, [[Science History Institute]]}}

Q-switched lasers are also used to remove [[tattoo]]s by shattering ink pigments into particles that are cleared by the body's [[lymphatic system]]. Full removal can take between six and twenty treatments depending on the amount and colour of ink, spaced at least a month apart, using different [[wavelength]]s for different coloured inks.<ref name="Distillations">{{cite journal|last1=Klett|first1=Joseph |title=Second Chances|url=https://www.sciencehistory.org/distillations/magazine/second-chances |journal=Distillations |publisher=[[Science History Institute]]|date=2018|volume=4 |issue=1 |pages=12–23|access-date=June 27, 2018 }}</ref> Nd:YAG lasers are currently the most favoured lasers due to their high peak powers, high repetition rates and relatively low costs. In 2013 a picosecond laser was introduced based on clinical research which appears to show better clearance with difficult-to-remove colours such as green and light blue.{{citation needed|date=April 2021}} Q-switched lasers can also be used to remove dark spots and fix other skin pigmentation issues.{{citation needed|date=April 2021}}