Light wavelengths within and around the visible spectrum are generally too large for light-matter interaction at the nanoscale. Plasmonic nanotips offer a cutting-edge solution for manipulating light by confining it into a nanometric volume and opening up a range of possibilities for its nanoscale applications. When combined with non-destructive optical techniques such as Raman spectroscopy and imaging, this plasmonic approach facilitates one to “see” the physical, chemical, and biological phenomena occurring at the nanometer scale, and even down to the sub-nanometer scale. Our group is actively engaged in inventing, developing, and improving world-class instrumentation for plasmonics-based optical techniques. This includes technologies such as tip-enhanced Raman spectroscopy/microscopy and plasmon nanofocusing, which we utilize for nano-investigation and nanoimaging of a diverse range of physical, chemical, and biological properties in a variety of samples. Additionally, these technologies are also applied in the precise control of chemical reactions and optical switching at the nanometer scale.