  The near field scanning optical microscopy (NSOM) is not only a tool for
imaging of sub-diffraction limited objects but also a prominent characteristic
tool for understanding the intrinsic properties of the nanostructures. In order
to understand the light-matter interactions in the near field regime using NSOM
technique with an excitation of 532 nm (2.33 eV), we selected an isolated
single semiconducting AlGaN nanowire (NW) of diameter ~120 nm grown via vapor
liquid solid (VLS) mechanism along with metallic Au nanoparticle (NP) catalyst.
The role of electronic transitions from different native defect related energy
states of AlGaN are discussed in understanding the NSOM images for the
semiconducting NW. The effect of strong surface plasmon resonance absorption of
excitation laser in the NSOM images for Au NP, involved in the VLS growth
mechanism of NWs, is also observed. Keywo
