Laser Emission from Ring Resonators Formed by a Quantum-Dot-Doped Single Polymer Nanowire

Laser emission from nanowire-based devices is important for nanophotonic applications. Here we report the observation of optically pumped laser emission from ring resonators formed by quantum-dot-doped single polymer nanowire. By assembling a 500 nm diameter single polymer nanowire with an optical loss coefficient of 70 cm^-1 to form a ring resonator with a short diameter of 20 μm and a large diameter of 40 μm, multimode laser emission with mode number of 9 is obtained in the wavelength region from 550 to 650 nm. The dominant emission is 600 nm wavelength with a line width of 0.8 nm, a Q factor of 400, and a low lasing threshold of 100 μJ/cm² under a 550 nm green laser pump.