Random lasing properties of dye solutions suspended with silver nanoshells are investigated. Unlike the case of metal nanoparticles with a dielectric layer to suppress high absorption rate which is seriously detrimental to lasing resonance, Ag nanoshells with cavity mode can concentrate electric field around the void centre and consequently lead to low loss.
This is supported by the finite-different time-domain method. The results suggest that Ag nanoshells nanostructures present a new approach towards well-controlled random lasers.