A surface plasmon NANO laser device

Abstract

A surface plasma nanolaser element includes a gain layer, a dielectric layer, and a resonant cavity. The gain layer can be photoexcited or electroexcited to generate photons. The resonant region has multiple nanoscale elongated trenches spaced apart along an alignment direction, exposing the dielectric layer, so that the photons can excite surface plasmas with hyperbolic dispersion characteristics in the resonant region. The surface plasmas couple with the photons in the dielectric layer and resonate in the resonant region to generate laser light leaving the surface plasma nanolaser element. Since this resonance mode is achieved by the hyperbolic dispersion characteristics of surface plasmas, it has a better confinement effect and is not limited by the optical diffraction limit, thus achieving a high quality factor in a very small volume.

Claims

1. A surface plasma nanolaser element, comprising: a gain layer that can be photoexcited or electroexcited to generate photons; a dielectric layer disposed on the gain layer; and a resonant cavity disposed on a surface of the dielectric layer opposite to the gain layer, and which can be divided into a resonant region and a continuous metal region surrounding the resonant region, the resonant region having a plurality of elongated trenches at nanoscale, spaced apart along a linear arrangement direction parallel to the surface of the dielectric layer opposite to the gain layer, exposing the dielectric layer, such that the photons can excite surface plasmas with hyperbolic dispersion characteristics in the resonant region, the surface plasmas coupling with the photons in the dielectric layer and resonating in the resonant region to generate a laser beam exiting the surface plasma nanolaser element.

2. The surface plasma nanolaser element as claimed in claim 1, wherein, Along the direction of this straight alignment, the surface plasma dispersion curve of the resonant region and the surface plasma dispersion curve of the continuous metal region do not share a common wave vector.

3. The surface plasma nanolaser element as claimed in claim 1, wherein, Each of the elongated grooves extends along a direction perpendicular to the direction of the straight line arrangement, and its width is less than or equal to the diffraction limit of the photon.

4. The surface plasma nanolaser element as claimed in claim 3, wherein, Each of these long grooves is shaped like a square column.

5. The surface plasma nanolaser element as claimed in claim 1, wherein, The material of the gain layer includes gallium arsenide.

6. The surface plasma nanolaser element as claimed in claim 1, wherein, The gain layer includes a heavily doped P-type layer connected to the dielectric layer.

7. The surface plasma nanolaser element as claimed in claim 1, wherein, The gain layer has a quantum well structure.

8. The surface plasma nanolaser element as claimed in claim 7, wherein, The gain layer includes, in sequence along the direction toward the resonant cavity, an N-type doped substrate, an N-type doped layer, a first barrier layer, an active layer, a second barrier layer, and a P-type doped layer.

9. The surface plasma nanolaser element as claimed in claim 1, wherein, The dielectric layer is made of silicon dioxide or magnesium difluoride.

10. The surface plasma nanolaser element as claimed in claim 1, wherein, The resonant cavity is made of gold, silver, or aluminum.

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