Chiroptical Amplification in Circularly Polarized Random Lasing Using Chiral Plasmonic Core–Shell Nanoparticles

Random lasers offer distinct advantages over conventional cavity-based lasers, including the possibility of using materials with varied shapes, sizes, and compositions, enabling versatile integration into disordered systems. In this paper, we report the generation of circularly polarized random laser emission from materials composed of chiral plasmonic core–shell Au@Au nanoparticles, titanium dioxide nanoparticles, and rhodamine 6G dye in ethanol solution. Different concentrations of chiral nanoparticles were investigated, and the concentration of titanium dioxide was carefully tuned to ensure that it did not interfere with the chiroptical properties arising from the chiral nanoparticles. The chiral Au@Au nanoparticles exhibited dissymmetry factors (gabs ≈+0.003), calculated from their circular dichroism spectra. Remarkably, under random lasing conditions, the system displayed emission with luminescence dissymmetry factor values reaching up to +0.24. The significant values of circular polarization in the emission open perspectives for the design of active sensors with preferential single-handed emission as well as for the development of chiral photonic materials incorporating emerging luminescent platforms.