a novel plasmonic nanolaser based on fano resonances with super low threshold

A novel plasmonic nanolaser is proposed based on a heptamer of silver nanoparticles surrounded by gain material. optical properties of the proposed laser are analyzed using the finite element method. the proposed laser has a super low threshold at the fano resonance wavelength, and when the gain coefficient reaches the laser threshold, the localized electric field intensity is greatly enhanced to produce the lasing mode. the fano resonance wavelength is redshifted as the dielectric material refractive index, and silver nanoparticle radius increases and gap distance decreases. the threshold remains below 0.1 at all times. optimizing the structural parameters of the heptamer or dielectric material gain coefficient allows the threshold to be reduced to 0.014 with corresponding localized electric field intensity greater than 104 v/m.