birefringence
noun
bi·re·frin·gence
ˌbī-ri-ˈfrin-jən(t)s 
plural birefringences
1
: the refraction of light in an anisotropic material (such as calcite) in two slightly different directions to form two rays
According to G. Blom of Philips, video disc acrylics must be optically clear and free of striations and birefringence. Clear vinyl often is highly birefringent.—
Technical Survey
Technical Surveycalled also double refraction
2
: the visual effect produced by birefringence
The diagnosis was made before scanning in 22 patients by the detection of deposits with apple-green birefringence …—Philip N. Hawkins et al.
Philip N. Hawkins et al.3
: the difference between the angles of refraction of light rays exhibiting birefringence
Examples of birefringence in a Sentence
Recent Examples on the Web
To investigate further, researchers designed a specialized battery cell that allowed direct observation of dendrite growth and used birefringence microscopy to measure stress levels in real time.
—
Jijo Malayil,
Interesting Engineering,
25 Mar. 2026
The femto-second lasers used for recording record nanostructures that can encode data in their width, height, depth, polarization and birefringence, hence the 5D name.
—
Thomas Coughlin,
Forbes.com,
18 Aug. 2025
Like ordinary cellophane, the birefringence can split light into separate directions, leading to weird optical illusions, distortions, and magnification—all from the simple presence of the magnetic field.
—
Paul Sutter,
Ars Technica,
17 June 2022
When light passes through this region of space where vacuum birefringence occurs, it gets polarized, but only if this phenomenon inherent to quantum field theory is true.
—
Ethan Siegel,
Forbes,
7 May 2021
The writing costs will be higher, though, since changing birefringence in glass requires fine control of a laser's polarization and intensity.
—
IEEE Spectrum,
15 July 2013
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Jijo Malayil,
Interesting Engineering,
25 Mar. 2026
The femto-second lasers used for recording record nanostructures that can encode data in their width, height, depth, polarization and birefringence, hence the 5D name.
—
Thomas Coughlin,
Forbes.com,
18 Aug. 2025
Like ordinary cellophane, the birefringence can split light into separate directions, leading to weird optical illusions, distortions, and magnification—all from the simple presence of the magnetic field.
—
Paul Sutter,
Ars Technica,
17 June 2022
When light passes through this region of space where vacuum birefringence occurs, it gets polarized, but only if this phenomenon inherent to quantum field theory is true.
—
Ethan Siegel,
Forbes,
7 May 2021
The writing costs will be higher, though, since changing birefringence in glass requires fine control of a laser's polarization and intensity.
—
IEEE Spectrum,
15 July 2013
Cite this Entry
“Birefringence.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/birefringence. Accessed 5 Jul. 2026.
Copy CitationMedical Definition
birefringence
noun
bi·re·frin·gence
ˌbī-ri-ˈfrin-jən(t)s
: the refraction of light in an anisotropic material in two slightly different directions to form two rays
also
: the visual effect produced by birefringence
The diagnosis was made before scanning in 22 patients by the detection of deposits with apple-green birefringence … —Philip N. Hawkins et al., The New England Journal of Medicine
Philip N. Hawkins et al., The New England Journal of Medicine Love words? Need even more definitions?
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