  We investigate hyper-doping, a promising approach to introduce a high
concentration of impurities into silicon beyond its solid solubility limit, for
its potential applications in near-infrared plasmonics. We systematically
explore the incorporation of dopants into silicon using ion implantation and
pulsed laser melting annealing processes. Reflectance spectra analysis shows an
achievable plasma wavelength of around 1.5 $\mu$m for dopant concentrations
exceeding 4 at.%. Complex refractive index data for the doped silicon samples
are extracted, revealing their potential for near-infrared plasmonic
applications. Moreover, we propose a fabrication process that allows for the
creation of hyper-doped silicon nanoparticles without the need for additional
masking steps. Our research paves the way for designing CMOS-compatible
plasmonic nanostructures operating in the telecommunication wavelength range.
The study's findings offer significant insights into the utilization of
hyper-doped silicon for advanced photonic and optoelectronic applications.
