Ultrastrong slow light in a metal nanoshell-semiconductor quantum dot-cell membrane hybrid system
Hong-Mei Gong, Lin-Wen Long, Xiao Ma +1 more
We propose a scheme for achieving ultrastrong slow light in a hybrid nanosystem consisting of a metallic nanoshell (MNS), a semiconductor quantum dot (SQD), and a cell membrane. The MNS is composed of a metallic inner core and a dielectric outer shell. We derive the analytical expressions for the linear susceptibility and group velocity index under the multipole approximation. It is shown that the amplitudes and positions of the absorption peaks, as well as the group velocity index, depend strongly on the exciton-pump detuning, MNS-SQD distance, dielectric shell thickness, and exciton-phonon coupling strength. Especially, the amplitude of the characteristic absorption peak associated with the cell membrane can be enhanced by over 2200 times by only tuning the exciton-phonon coupling strength within an extremely narrow range. In an intermediate exciton-phonon coupling regime, the group velocity index rises abruptly from 86.13 to 2.87 × 10 11 with the pump intensity varied from 10 GHz 2 to 22.41 GHz 2 . Furthermore, we demonstrate that the precise monitoring of the cellular carcinogenesis degree can be realized by detecting the fast-to-slow light switching point, with the corresponding proportion of cancerous cells as low as 1.71%. Our findings exhibit broad application prospects in optical signal amplifiers and biosensors.
Optics Express•Aug 31, 2026•0 citations