Patent ID: 8017406

Claim:
A method for generating and amplifying a nanoscale oscillating electric field via surface plasmon amplification by stimulated emission of radiation (SPASER) action, comprising the steps of: providing a nanostructure comprising a resonant medium possessing surface plasmons and a surface plasmon mode therein, and an active medium, adjacent to the resonant medium, comprising an object having at least one two-level emitter with significant dipole oscillator strength for a transition at a transition frequency that overlaps with a spectral frequency range of the surface plasmons; providing an energy source; applying energy from the energy source to the active medium to achieve transition of the at least one two-level emitter within the active medium, thereby causing a population inversion in the active medium, a transfer of energy from the active medium to the surface plasmons on the resonant medium and a stimulated emission of the surface plasmons into the resonant medium, wherein the energy source provides a power exceeding a threshold so as to satisfy the SPASER action condition α n >0, where α n =(A n −γ n )/γ n is a dimensionless gain, γ n is the relaxation rate of the surface plasmon mode, and A n is Einstein's coefficient describing the net stimulated emission rate of the surface plasmon mode, A n being proportional to the transition strength and to a spatial overlap factor between the population inversion and the intensity of the surface plasmon mode, and whereby the SPASER action causes a build-up of a macroscopic number of the surface plasmons in the surface plasmon mode.