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Title: Topological nanospaser
Abstract We propose a nanospaser made of an achiral plasmonic–metal nanodisk and a two-dimensional chiral gain medium – a monolayer nanoflake of a transition-metal dichalcogenide (TMDC). When one valley of the TMDC is selectively pumped (e.g. by a circular-polarized radiation), the spaser (surface plasmon amplification by stimulated emission of radiation) generates a mode carrying a topological chiral charge that matches that of the gain valley. There is another, chirally mismatched, time-reversed mode with exactly the same frequency but the opposite topological charge; it is actively suppressed by the gain saturation and never generates, leading to a strong topological protection for the generating matched mode. This topological spaser is promising for use in nano-optics and nanospectroscopy in the near field especially in applications to biomolecules that are typically chiral. Another potential application is a chiral nanolabel for biomedical applications emitting in the far field an intense circularly polarized coherent radiation.  more » « less
Award ID(s):
1741691
PAR ID:
10200036
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
Nanophotonics
Volume:
9
Issue:
4
ISSN:
2192-8614
Page Range / eLocation ID:
865 to 874
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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