80th CEMS Colloquium


Prof. Takashige Omatsu (Chiba University)


17:30 - 18:30, February 26, 2020 (Wednesday)


Okochi-Hall, RIKEN


Twisted Light and Matter Interaction


Optical vortex, i.e. ‘twisted light’, carries an orbital angular momentum (OAM), characterized by an integer termed a topological charge,  and an annular spatial profile, associated with its helical wavefront 1. To date, the optical vortex has been widely studied in a myriad of fields on a nano/micro-scale, such as optical trapping and manipulation 2, and laser scanning fluorescent microscopy with a spatial resolution beyond the diffraction limit 3. Interestingly, optical vortex itself can potentially propagate though air turbulence with less degradation than conventional Gaussian beams 4. Thus, applications of optical vortex, including quantum communications 5, fiber-based or free-space telecommunications 6, and environmental optics, have been also proposed.

The interaction between OAM of light and materials further offers new fundamental physical phenomena, in which the optical vortex ‘twists’ various materials, such as metals, silicon, azopolymers, and even high viscosity liquids to form ‘twisted’ structures on a nano/micro-scale with the aid of spin angular momentum (SAM), associated with the helical electric field of circularly polarization 7. Going beyond traditional studies based on optical vortex and OAM, such ‘twisted’ structures should open new research avenues towards advanced materials sciences and technologies.

Here, we review the interaction between OAM of light and matters, showing us the most striking, diverse structures and phenomena.

1) L. Allen, M. W. Beijersbergen, R. J. C. Spreeuw, J. P. Woerdman, Phys. Rev. A 45(11), 8185–8189 (1992).
2) K. Dholakia, T. Čižmár, Nat. Photonics 5(6), 335–342, (2011).
3) M. Kamper, H. Ta, N. A. Jensen, S. W. Hell, S. Jakobs, Nat. Commun. 9(1), 4762 (2018).
4) Y. Li, L. Yu, Y. Zhang, Opt. Express 25(11), 12203–12215 (2017).
5) G. Molina-Terriza, J. P. Torres, L. Torner, Nat. Phys. 3(5), 305–310 (2007).
6) J. Wang, Photonics Res. 4(5), B14 (2016).
7) T. Omatsu, K. Miyamoto, K. Toyoda, R. Morita, Y. Arita, K. Dholakia, Adv. Optical Mater. 7(14), 1801672 (2019).