Research Highlight: Odom
Continuous-wave Upconverting Lasing from Sub-wavelength Plasmons
Continuous-wave small lasers are critical for integration with optoelectronic devices and optimal modulation of optical interactions. However, insufficient optical gain and thermal instabilities have limited nanoscale lasers to pulsed pump sources and/or low-temperature operation. We developed a materials platform that realized continuous-wave nanoscale lasing at room temperature with record-low thresholds and high stability. Single-color lasing was achieved from upconverting nanoparticles conformally coated on silver nanopillar arrays. The intense optical fields localized near the nanopillars result in a threshold of 70 W/cm2, orders of magnitude lower than other small lasers. Our small lasers can be excited under near-infrared pumping that allows penetration into tissues, and emit ultra-stable light at visible frequencies. The continuous wave, low-power characteristics will open numerous new applications, especially in biological imaging, quantum circuits and microprocessors for ultra-fast and low-power electronics.