Q-plate

Last updated
A q-plate can convert a right-polarized beam into a beam with an OAM of -2h, and a left-polarized beam into a +2h state. Q-plate.png
A q-plate can convert a right-polarized beam into a beam with an OAM of -2ħ, and a left-polarized beam into a +2ħ state.

A q-plate is an optical device that can form a light beam with orbital angular momentum (OAM) from a beam with well-defined spin angular momentum (SAM). Q-plates are based on the SAM-OAM coupling that may occur in media that are both anisotropic and inhomogeneous, such as an inhomogeneous anisotropic birefringent waveplate. Q-plates are also currently realized using total internal reflection devices, liquid crystals, metasurfaces based on polymers, and sub-wavelength gratings. [1]

The sign of the OAM is controlled by the input beam's polarization. [2] [3]

References

  1. Petrov, N. V.; Sokolenko, B.; Kulya, M. S.; Gorodetsky, A.; Chernykh, A. V. (2022-08-02). "Design of broadband terahertz vector and vortex beams: I. Review of materials and components". Light: Advanced Manufacturing. 3 (4): 43. doi: 10.37188/lam.2022.043 .
  2. Marrucci, L.; Manzo, C.; Paparo, D. (2006-04-28). "Optical Spin-to-Orbital Angular Momentum Conversion in Inhomogeneous Anisotropic Media". Physical Review Letters. 96 (16): 163905. arXiv: 0712.0099 . Bibcode:2006PhRvL..96p3905M. doi:10.1103/PhysRevLett.96.163905. PMID   16712234.
  3. Karimi, Ebrahim; Piccirillo, Bruno; Nagali, Eleonora; Marrucci, Lorenzo; Santamato, Enrico (2009-06-08). "Efficient generation and sorting of orbital angular momentum eigenmodes of light by thermally tuned q-plates". Applied Physics Letters. 94 (23): 231124. arXiv: 0905.0562 . Bibcode:2009ApPhL..94w1124K. doi:10.1063/1.3154549. ISSN   0003-6951.