The 50 to 150nm thick nanolasers described in the Nature Materials journal under the title “Ultralow-threshold, continuous-wave upconverting lasing from subwavelength plasmons”, consist of Yb3+/Er3+-co-doped upconverting nanoparticles conformally coated on Ag nanopillar arrays supporting a single, sharp lattice plasmon cavity mode. The device exhibits a greater than wavelength λ/20 field confinement in the vertical dimension, and the intense electromagnetic near-fields localized in the vicinity of the nanopillars result in a lasing threshold of 70 W cm−2, orders of magnitude lower than other small lasers, the authors report.
“Our tiny lasers operate at powers that are orders of magnitude smaller than observed in any existing lasers,” said P. James Schuck, an associate professor of mechanical engineering at Columbia and co-leader of the study.
The nanolaser can operate in “extremely confined spaces” including quantum circuits and microprocessors for ultrafast and low-power electronics. It is made mainly of glass, which itself is biocompatible. The technology can also be excited by longer wavelengths of light while emitting at shorter wavelengths.