A light amplifying device for surface enhanced Raman spectroscopy is disclosed herein. The device includes a dielectric layer having two opposed surfaces. A refractive index of the dielectric layer is higher than a refractive index of a material or environment directly adjacent thereto. At least one opening is formed in one of the two opposed surfaces of the dielectric layer, and at least one nano-antenna is established on the one of the two opposed surfaces of the dielectric layer. A gain region is positioned in the dielectric layer or adjacent to another of the two opposed surfaces of the dielectric layer.