Size reduction of a semiconductor nanowire laser using metal coating

We explore the possibility of coating semiconductor nanowires with metal (Ag) to reduce the size of nanowire lasers operating at photon energies around 0.8–2 eV. Our results show that the material gain of a typical III-V semiconductor in nanowire may be sufficient to compensate Joule losses of such metal as Ag. The most promising mode to achieve lasing seem to be TM01 near its cutoff. To calculate the guiding properties of metal coated nanowires, we developed a finite-difference discretization approach, the details of which we also present. This approach allowed us to treat accurately the wire/metal interface and to include nonperturbatively the imaginary parts of dielectric constants of the semiconductor core and metal cladding.