Ultrafast all-optical switching enabled by epsilon-near-zero-tailored absorption in metal-insulator nanocavities

Abstract

Ultrafast control of light−matter interactions is fundamental in view of new technological frontiers of information processing. However, conventional optical elements are either static or feature switching speeds that are extremely low with respect to the time scales at which it is possible to control light. Here, we exploit the artificial epsilon-near-zero (ENZ) modes of a metal-insulator-metal nanocavity to tailor the linear photon absorption of our system and realize a nondegenerate all-optical ultrafast modulation of the reflectance at a specific wavelength. Optical pumping of the system at its high energy ENZ mode leads to a strong redshift of the low energy mode because of the transient increase of the local dielectric function, which leads to a sub-3-ps control of the reflectance at a specific wavelength with a relative modulation depth approaching 120%.

Untargeted effects in organic exciton–polariton transient spectroscopy: A cautionary tale

“…Indeed, the transient response of such purely photonic structures is well characterized. 78,79 Here, the dominant effect is likely pumpinduced changes to the refractive index of the metallic mirrors, similar to suggestions using TIPSpentacene microcavities. 63 Similar effects can be obtained within organic films, as reported for instance from a PMMA waveguide mode not coupled to any electronic excitations.…”

“…The parameters considered in this analysis are as follows: 1) reduction in organic dye layer absorption, to replicate the effect of ground-state bleaching; 2) thickness of the organic layer (keeping the total film absorption constant), to capture thermal expansion; and background refractive index changes in 3) the organic polymer matrix and 4) the mirror material (metal or dielectric), in accord with previous transient studies on photonic structures. 78,79 Within this scheme we only calculate steady-state optical properties; our assumption is that any spectral dynamics arise from the mechanism of the underlying effect. For instance, within the twotemperature model of Liu et al, the <10 ps dynamics in microcavity transient reflectivity could be predominantly described by carrier thermalization.…”

“…63 Similar dynamics are reported for hot carrier cooling in other photonic structures. 78,79 Ground-state bleaching should roughly follow the dynamics of the bare film, resulting in persistent signatures on the order of nanoseconds. These effects span the sub-ps to ns timescale and could easily be reconciled with our measured dynamics.…”

Study on the Nanosensor Based on a MIM Waveguide with a Stub Coupled with a Horizontal B-Type Cavity

“…In an optical switching field, Yang et al designed a Berreman-type perfect absorber which was switched on and off within 800 fs [23]. Kuttruff et al realized a nondegenerate all-optical ultrafast modulation which realized that the control of the reflectance was no more than 3 ps at a specific wavelength [24].…”

Ultrafast Nonlinear Pulse Propagation Dynamics in Metal–Dielectric Periodic Photonic Architectures

“…The ultrafast dynamics and the higher-order nonlinearities of MD metamaterials are dominated by the contribution of metal's noninstantaneous Kerr nonlinearity [15][16][17][18][19] and several numerical studies have been carried out in 1D and cylindrical type 2D geometries for the specific spectral region of interest. [16,17] Especially, the numerical realization of the ultrafast pulse propagation in wavelength-ordered multilayer MD structure is not straight forward because of a large variety of spatial and temporal effects, ranging from self-focusing and self-phase modulation to the formation of solitons.…”