Plasmonic Green Nanolaser Based on a Metal–Oxide–Semiconductor Structure

Abstract

Realization of smaller and faster coherent light sources is critically important for the emerging applications in nanophotonics and information technology. Semiconductor lasers are arguably the most suitable candidate for such purposes. However, the minimum size of conventional semiconductor lasers utilizing dielectric optical cavities for sustaining laser oscillation is ultimately governed by the diffraction limit (∼(λ/2n)(3) for three-dimensional (3D) cavities, where λ is the free-space wavelength and n is the refractive index). Here, we demonstrate the 3D subdiffraction-limited laser operation in the green spectral region based on a metal-oxide-semiconductor (MOS) structure, comprising a bundle of green-emitting InGaN/GaN nanorods strongly coupled to a gold plate through a SiO(2) dielectric nanogap layer. In this plasmonic nanocavity structure, the analogue of MOS-type "nanocapacitor" in nanoelectronics leads to the confinement of the plasmonic field into a 3D mode volume of 8.0 × 10(-4) μm(3) (∼0.14(λ/2n)(3)).

Electric Spaser in the Extreme Quantum Limit

“…In a direct contrast, the possibility of the optically pumped strongly 3d-confined spaser has been both theoretically shown [1,3,26,27] and experimentally demonstrated [6,7,14,18]. Here we theoretically establish that the electrically-pumped spaser is fundamentally possible.…”

“…The heat dissipation in the electrically-and optically pumped spasers should be on the same order of magnitude. Note that the opticallypumped strongly 3d-confined nanospasers do work without a damage in the wide range of intensities [6,7,14,18].…”

“…The spaser is based on compensation of optical losses in metals by gain in the active medium (nanoshell) overlapping with the surface plasmon (SP) eigenmodes of the metal plasmonic nanosystem. There are many experimentally observed and investigated spasers where the gain medium consisted of dye molecules [6][7][8], unstructured semiconductor nanostructures and nanoparticles [9][10][11][12][13][14][15][16][17][18], or quantum-confined semiconductor heterostructures: quantum dots (QDs) [19,20], quantum wires (QWs), or quantum wells [21].Classified by mode confinement, there are the spasers with one-dimensional [9,11,13], two-dimensional [10], or three-dimensional (3d) confinement [6,7,18]. The spasers can also be classified by the spasing-eigenmode type, which can be either localized surface plasmons (SPs) [6,7,14,18], or surface plasmon polaritons (SPPs) [22,23] as in the rest of the cases.…”

“…The spaser is based on compensation of optical losses in metals by gain in the active medium (nanoshell) overlapping with the surface plasmon (SP) eigenmodes of the metal plasmonic nanosystem. There are many experimentally observed and investigated spasers where the gain medium consisted of dye molecules [6][7][8], unstructured semiconductor nanostructures and nanoparticles [9][10][11][12][13][14][15][16][17][18], or quantum-confined semiconductor heterostructures: quantum dots (QDs) [19,20], quantum wires (QWs), or quantum wells [21].…”

Theoretical study of plasmonic lasing in junctions with many molecules

“…These quantum emitters should, in turn be excited, e.g., by optical pumping [3][4][5][6][7][8][9][10][11][12] or by electrical injection [13,14]. In Ref.…”