Gain-assisted lossless surface plasmon polariton excitation in semiconductor quantum dots

We present a technique based on electromagnetically induced transparency (EIT) phenomena for coupler-free excitation of gain-assisted lossless surface plasmon polariton (SPP) in a quantum dots (QDs) of the ladder-type configuration. We consider a three-layer structure with a bottom layer made of a QD system, a middle layer of metal film, and a top transparent layer made of vacuum or air. The bottom layer of the three layers is thought to be the most important. It is made possible for SPPs to be excited without a coupler by the amplification in EIT phenomenon that takes place in QDs. The momentum imbalance between light and SPP is eliminated by the EIT that is seen in QDs. It has been found that if the permittivity of the QD medium is less than one, the momentum match may occur at a specific resonance angle. In order to compensate for the losses, we introduce gain into our system by incorporating the incoherent pump field, the strength of the control field, and the system-related parameters. This causes sharp surface plasmon resonance (SPR) to arise. As a result of the strength of the control field and incoherent pumping, we have the ability to coherently regulate the SPP propagation duration. In addition to this, we investigate how the thickness of the metal coating influences SPPs. Our suggested scheme for the generation of SPP might be beneficial in photodetectors, sensors, polarizers and lithography.