Coherent perfect absorber

A coherent perfect absorber (CPA), or anti-laser, is a device which absorbs coherent waves, such as coherent light waves, and converts them into some form of internal energy, e.g. heat or electrical energy.[1][2] It is the time-reversed counterpart of a laser.[3] Coherent perfect absorption allows control of waves with waves (light with light) without a nonlinear medium. The concept was first published in the July 26, 2010, issue of Physical Review Letters, by a team at Yale University led by theorist A. Douglas Stone and experimental physicist Hui W. Cao.[4][5] In the September 9, 2010, issue of Physical Review A, Stefano Longhi of Polytechnic University of Milan showed how to combine a laser and an anti-laser in a single device.[6] In February 2011 the team at Yale built the first working anti-laser.[7][8] It is a two-channel CPA device which absorbs two beams from the same laser, but only when the beams have the correct phases and amplitudes.[9] The initial device absorbed 99.4 percent of all incoming light, but the team behind the invention believe it will be possible to achieve 99.999 percent.[7] Originally implemented as a Fabry-Pérot cavity that is many wavelengths thick, the optical CPA operates at specific optical frequencies. In January 2012, thin-film CPA has been proposed by utilizing the achromatic dispersion of metal-like materials, exhibiting the unparalleled bandwidth and thin profile advantages.[10] Shortly after, CPA was observed in various thin film materials, including photonic metamaterial,[11] multi-layer graphene,[12] single[13] and multiple[14] layers of chromium, as well as microwave metamaterial.[15]

Coherent perfect absorption arises from destructive interference of transmitted and reflected waves, which traps wave energy within an absorber until it is absorbed.
Real (n) and imaginary (k) parts of the refractive index of strongly doped silicon and the corresponding coherent absorption for a film thickness of 150 nm.[10]
  1. ^ Gmachl, Claire F. (2010). "Laser science: Suckers for light". Nature. 467 (7311): 37–39. Bibcode:2010Natur.467...37G. doi:10.1038/467037a. PMID 20811446.
  2. ^ "Behold, the Antilaser". Science News. Archived from the original on 2012-11-15. Retrieved 2010-09-07.
  3. ^ Longhi, Stefano (2010). "Backward lasing yields a perfect absorber". Physics. 3: 61. Bibcode:2010PhyOJ...3...61L. doi:10.1103/Physics.3.61.
  4. ^ Chong, Y.; Ge, Li; Cao, Hui; Stone, A. (2010). "Coherent Perfect Absorbers: Time-Reversed Lasers". Physical Review Letters. 105 (5): 053901. arXiv:1003.4968. Bibcode:2010PhRvL.105e3901C. doi:10.1103/PhysRevLett.105.053901. PMID 20867918. S2CID 17003350.
  5. ^ Stefano Longhi (2010). "Backward lasing yields a perfect absorber". Physics. 3: 61. Bibcode:2010PhyOJ...3...61L. doi:10.1103/Physics.3.61.
  6. ^ Stefano Longhi (2010). "PT-symmetric laser absorber". Physical Review A. 82 (3): 031801. arXiv:1008.5298. Bibcode:2010PhRvA..82c1801L. doi:10.1103/PhysRevA.82.031801. S2CID 119157414. (Synopsis by Mark Saffman.)
  7. ^ a b "Scientists Build the World's First Anti-laser". Yale University. 2011-02-17. Archived from the original on 2011-02-21. Retrieved 2011-02-17.
  8. ^ "Scientists build the world's first anti-laser". BBC. 2011-02-17. Retrieved 2011-02-17.
  9. ^ Wan, W.; Chong, Y.; Ge, L.; Noh, H.; Stone, A. D.; Cao, H. (2011). "Time-Reversed Lasing and Interferometric Control of Absorption". Science. 331 (6019): 889–892. Bibcode:2011Sci...331..889W. doi:10.1126/science.1200735. PMID 21330539. S2CID 206531272.
  10. ^ a b Pu, M.; Feng, Q.; Wang, M.; Hu, C.; Huang, C.; Ma, X.; Zhao, Z.; Wang, C.; Luo, X. (17 January 2012). "Ultrathin broadband nearly perfect absorber with symmetrical coherent illumination". Optics Express. 20 (3): 2246–2254. Bibcode:2012OExpr..20.2246P. doi:10.1364/oe.20.002246. PMID 22330464.
  11. ^ Zhang, J.; MacDonald, K. F.; Zheludev, N. I. (6 July 2012). "Controlling light-with-light without nonlinearity". Light: Science & Applications. 1: e18. arXiv:1203.6110. doi:10.1038/lsa.2012.18.
  12. ^ Rao, S. M.; Heitz, J. J. F.; Roger, T.; Westerberg, N.; Faccio, D. (2014). "Coherent control of light interaction with graphene". Optics Letters. 39: 5345–5374. arXiv:1406.6217. doi:10.1364/OL.39.005345.
  13. ^ Goodarzi, A.; Ghanaatshoar, M. (2016). "Controlling light by light: photonic crystal-based coherent all-optical transistor". Journal of the Optical Society of America B. 33: 1594–1599. doi:10.1364/JOSAB.33.001594.
  14. ^ Vetlugin, A. N.; Guo, R.; Soci, C.; Zheludev, N. I. (2022). "Deterministic generation of entanglement in a quantum network by coherent absorption of a single photon". Physical Review A. 106: 012402. doi:10.1103/PhysRevA.106.012402. hdl:10356/170804.
  15. ^ Li, S.; Luo, J.; Anwar, S.; Li, S.; Lu, W.; Hang, Z.H.; Lai, Y.; Hou, B.; Shen, M.; Wang, C. (2015). "Broadband Perfect Absorption of Ultrathin Conductive Films with Coherent Illumination: Super Performance of Electromagnetic Absorption". Physical Review B. 91 (22): 220301. arXiv:1406.1847. Bibcode:2015PhRvB..91v0301L. doi:10.1103/PhysRevB.91.220301. S2CID 118609773.