This book describe the research on controlling of electron plasma by metal nano structuring which in turn provide the efficient control on surface plasmons (SPs). These SPs are the waves which propagate on the interface of noble metal and dielectric whose frequency is dependent on the bulk electron plasma frequency of the metal. Efficient coupling of SPs with Photon in dielectric provide field localisation on subwavelength scale and these nanoscale light sources are needed in Heat Assisted Magnetic recording (HAMR) systems. Structuring metals (1-D Rectangular diffraction grating) on the nanometre scale enables to couple photons to these SPs. Apart from this, of particular interest here is to use high refractive index substrate, e.g. Gallium Phosphide (GaP) which is photo-luminescence used for ohmic loss compensation on 50nm Gold film deposited on GaP. The GaP is also used to emulate Vertical Cavity Surface emitting laser (VCSEL) in order to provide cheaper alternative of light source being used in HAMR technology.