Induced Transparency in Plasmon–Exciton Nanostructures for Sensing Applications

Abstract

The effect of induced transparency, which is related to photoinduced bleaching of photoabsorbers, is being intensely studied and has many applications in the field of sensing. Along with this classical effect, numerous studies on induced transparency in coupled plasmon-exciton systems, which is accompanied by the formation of hybrid states, have been recently published. The formation of a new coupled system results in various spectral modifications. For example, induced transparency manifests itself as a narrow dip in the absorption spectrum of a coupled system. This effect can be used in sensing, the feasibility of which is the main objective here, where a variety of materials and methods for obtaining the induced transparency are considered. Various morphologies and geometries of plasmonic nanoparticles are discussed as well as types of molecular absorbers to assess the most favorable combinations for the evolvement of induced transparency. The potential applications of the induced transparency effect in sensing and molecular diagnostics are summarized.As shown above, the IT effect is highly sensitive to several parameters of the composite system: the distance between the absorber and the plasmonic structure, their mutual arrangement, and the type and properties of the absorber itself. At the same time, the

Selective switching of multiple plexcitons in colloidal materials: directing the energy flow at the nanoscale

“…58 There has been a lot of debate on the nature of plexcitons in the intermediate coupling regime. [55][56][57]59,60 To distinguish between the intermediate and the strong coupling regimes, PL measurements have emerged as a valuable tool. 55,61,62 Indeed, while in both regimes, the extinction signal has two maxima, PL is an incoherent phenomenon, and thus it cannot display Fano interference.…”

“…Similar geometries have already been suggested for NPs coupled to quantum dots. 55,60,62,73 In this condition, the electro-magnetic field is strongly confined in the inter-particle space. When a molecule or a quantum dot is placed there, its absorption can be strongly enhanced, causing an induced transparency phenomenon and the appearance of the typical Fano dip, like in our case.…”

Light‐Controlled Near‐Field Energy Transfer in Plasmonic Metasurface Coupled MoS2Monolayer

“…Resonance. [39] Besides plasmon-2D semiconductors , [27,28] applications in other plasmon-exciton coupling systems, such as plasmon-quantum dots [40,41] and plasmon-dye molecules systems, [42] have also been investigated.…”

“…[ 4,33,34 ] Different coupling mechanisms of plasmonic nanostructures and 2D semiconductor systems have been reported, including electromagnetic field enhancement, [ 28,35 ] hot electron doping, [ 3 ] strong coupling, [ 27,36,37 ] valleytronic modulation, [ 34,38 ] and dark‐exciton‐mediated Fano Resonance. [ 39 ] Besides plasmon‐2D semiconductors , [ 27,28 ] applications in other plasmon‐exciton coupling systems, such as plasmon‐quantum dots [ 40,41 ] and plasmon‐dye molecules systems, [ 42 ] have also been investigated.…”

Polariton-assisted splitting of broadband emission spectra of strongly coupled organic dye excitons in tunable optical microcavity

“…Depending on the ratio between these rates, two coupling regimes can be distinguished: weak and strong coupling. Weak coupling regime takes place when damping rates prevail over coupling rate [9]. In this regime, the spontaneous emission rate of the emitter is modified by altering the photon density of states, which is also known as Purcell effect [10].…”