Millimeter-Scale Spatial Coherence from a Plasmon Laser
Coherent light sources have been demonstrated based on a wide range of nanostructures, however, little effort has been devoted to probing their underlying coherence properties. Here, we report long-range spatial coherence of lattice plasmon lasers constructed from a periodic array of gold nanoparticles and a liquid gain medium at room temperature. By combining spatial and temporal interferometry, we demonstrate millimeter-scale (∼1 mm) spatial coherence and picosecond (∼2 ps) temporal coherence. The long-range spatial coherence occurs even without the presence of strong coupling with the lattice plasmon mode extending over macroscopic distances in the lasing regime. This plasmonic lasing system thus provides a platform for understanding the emergence of long-range coherence from collections of nanoscale resonators and points toward novel types of distributed lasing sources.
Hoang, T., Akselrod, G., Yang, A., Odom, T., & Mikkelsen, M. (2017). Millimeter-Scale Spatial Coherence from a Plasmon Laser. Nano Letters, 17 (11), 6690-6695. https://doi.org/10.1021/acs.nanolett.7b02677