  We consider plasmonic nanoantennas immersed in active host medium.
Specifically shaped metal nanoantennas can exhibit strong magnetic properties
in the optical spectral range due to the excitation of Magnetic Plasmon
Resonance (MPR). A case when a metamaterial comprising such nanoantennas can
demonstrate both "left-handiness" and negative permeability in the optical
range is considered. We show that high losses predicted for optical "left-
handed" materials can be compensated in the gain medium. Gains required to
achieve local generation in such magnetic active metamaterials are calculated
for real metals. We propose plasmonic nanolaser, where the metal nanoantenna
operates like a resonator. The size of the proposed plasmonic laser is much
smaller than the wavelength. Therefore, it can serve as a very compact source
of EM radiation.
