Editing Holography (section)

===Holographic interferometry===
{{Main|Holographic interferometry}}

Holographic interferometry (HI) is a technique that enables static and dynamic displacements of objects with optically rough surfaces to be measured to optical interferometric precision (i.e. to fractions of a wavelength of light).<ref>{{cite journal | last1 = Powell | first1 = RL | last2 = Stetson | first2 = KA | year = 1965 | title =  Interferometric Vibration Analysis by Wavefront Reconstruction| journal = J. Opt. Soc. Am. | volume = 55 | issue = 12 | pages = 1593–8 | doi = 10.1364/josa.55.001593 | bibcode = 1965JOSA...55.1593P }}</ref><ref>{{cite book |last1=Jones |first1=Robert |last2=Wykes |first2=Catherine |title=Holographic and Speckle Interferometry |date=1989 |publisher=Cambridge University Press |location=Cambridge |isbn=0-521-34417-4}}</ref> It can also be used to detect optical-path-length variations in transparent media, which enables, for example, fluid flow to be visualized and analyzed. It can also be used to generate contours representing the form of the surface or the isodose regions in radiation dosimetry.<ref>{{cite journal|last1=Beigzadeh |first1=A.M. |last2=Vaziri |first2=M.R. Rashidian |last3=Ziaie |first3=F. |title=Modelling of a holographic interferometry based calorimeter for radiation dosimetry|journal=Nuclear Instruments and Methods in Physics Research A|date=2017|volume=864|pages=40–49|doi=10.1016/j.nima.2017.05.019|bibcode=2017NIMPA.864...40B}}</ref>

It has been widely used to measure stress, strain, and vibration in engineering structures.