Probing and control of guided exciton-polaritons in a 2D semiconductor-integrated slab waveguide
preprintposted on 2023-05-24, 16:01 authored by Valeriy I. Kondratyev, Dmitry V. Permyakov, Tatyana V. Ivanova, Ivan V. Iorsh, Dmitry N. Krizhanovskii, Maurice S. Skolnick, Vasily Kravtsov, Anton K. Samusev
Guided 2D exciton-polaritons, resulting from the strong coupling of excitons in semiconductors with non-radiating waveguide modes, provide an attractive approach towards developing novel on-chip optical devices. These quasiparticles are characterized by long propagation distances and efficient nonlinear interaction. However, as guided exciton-polaritons are uncoupled from the free space, it is challenging to investigate them using conventional far-field spectroscopy techniques. Here we demonstrate a powerful approach for probing and manipulating guided polaritons in a Ta$_2$O$_5$ slab integrated with a WS$_2$ monolayer using evanescent coupling through a high-index solid immersion lens. Tuning the nanoscale gap between the lens and the sample, we demonstrate in-situ control over radiative losses and Rabi splitting of guided polaritons at ambient conditions. This extra degree of freedom allows for extracting all the intrinsic parameters of the strongly coupled system under study. Our results enable the future development of integrated optics employing room-temperature exciton-polaritons in 2D semiconductor-based structures.