Plasmonic Nanostars as Efficient Broadband Scatterers for Random Lasing

Huge spectral coverage of random lasing throughout the visible up to the infrared range is achieved with star-shaped gold nanoparticles ("nanostars"). As intrinsically broadband scattering centers, the nanostars are suspended in solutions of various laser dyes, forming randomly arranged resonators which support coherent laser modes. The narrow emission line widths of 0.13 nm or below suggest that gold nanostars provide an efficient coherent feedback for random lasers over an extensive range of wavelengths, all together spanning almost a full optical octave from yellow to infrared.