Second-order coherence properties of metallic nanolasers
Prof. Mercedeh Khajavimhan, in collaborations with Prof. Morandotti’s team, reports on the second-order coherence functions of nanoscale lasers.
Second-order coherence measurement results for nanoscale disk-shaped lasers. The g2(τ) measurements of the emitted light from the disk- shaped nanolaser as well as the corresponding emission spectra in a semi-logarithmic scale for disk radii of (a), (b) 250 nm and (c), (d) 900 nm.
Due to the high spontaneous emission coupled into the resonance mode in metallic nanolasers, there has been a debate concerning the coherence properties of this family of light sources. The second-order coherence function can unambiguously determine the nature of a given radiation. In this paper, an approach to measure the second-order coherence function for broad linewidth sources in the near-infrared telecommunication band is established based on a modified Hanbury Brown and Twiss configuration. Using this setup, it is shown that metallic coaxial and disk-shaped nanolasers with InGaAsP multiple quantum-well gain systems are indeed capable of generating coherent radiation.