This second volume in the Handai Nanophotonics book series covers the area of Nanoplasmonics, a recent hot topic in the field of nanophotonics, impacting a diverse range of research disciplines from information technology and nanotechnology to the bio- and medical sciences. The interaction between photons and metal nanostructures leads to interesting and extraordinary scientific phenomena and produces new functions for nano materials and devices. Newly discovered physical phenomena include local mode of surface plasmon polariton excited in nanoparticles, hot spots on nano-rods and nano-cones, long range mode of surface plasmons excited on thin metal films, and dispersion relationship bandgaps of surface plasmons in periodic metal structures. These have been applied to, for example, single molecule detection and nano-imaging/spectroscopy, photon accumulation for lasing applications, optical nano-waveguides and nano-circuits.