Polaritonic modes in low-dimensional materials enable strong light-matter interactions and the manipulation of light on nanometer length scales. Very recently, a new class of polaritons has attracted considerable interest in nanophotonics: image polaritons in van der Waals crystals, manifesting when a polaritonic material is in close proximity to a highly conductive metal, so that the polaritonic mode couples with its mirror image. Image modes constitute an appealing nanophotonic platform, providing an unparalleled degree of optical field compression into nanometric volumes while exhibiting lower normalized propagation loss compared to conventional polariton modes in van der Waals crystals on nonmetallic substrates. Moreover, the ultra-compressed image modes provide access to the nonlocal regime of light-matter interaction. In this review, we systematically overview the young, yet rapidly growing, field of image polaritons. More specifically, we discuss the dispersion properties of image modes, showcase the diversity of the available polaritons in various van der Waals materials, and highlight experimental breakthroughs owing to the unique properties of image polaritons.
Bibliografisk noteFunding Information:
Research funding: This work was supported by the Samsung Research Funding & Incubation Center of Samsung Electronics (Grant No. SRFC-IT1702-14) and National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant No. 2021R1I1A1A01057510) and the Ministry of Science and ICT (Grant No. 2017R1E1A1A01074323). N.A.M. is a VILLUM Investigator supported by VILLUM FONDEN (Grant No. 16498). J.D.C. is a Sapere Aude research leader supported by Independent Research Fund Denmark (Grant No. 0165-00051B). This work was also supported by the BK21 FOUR Program through the NRF funded by Ministry of Education.
© 2021 Sergey G. Menabde et al., published by De Gruyter, Berlin/Boston 2021.