High Circular Polarized Nanolaser with Chiral Gammadion Metal Cavity
Cheng-Li Yu, Yu-Hao Hsiao, Chiao‐Yun Chang, Pi-Ju Cheng, Hsiang‐Ting Lin, Ming-Sheng Lai, Hao‐Chung Kuo, Shu‐Wei Chang, Min‐Hsiung Shih
Abstract
We demonstrate a circularly polarized laser with the metal-gallium-nitride gammadion nanocavities. The ultraviolet lasing signal was observed with the high circular dichroism at room temperature under pulsed optical pump conditions. Without external magnetism which breaks the time-reversal symmetry to favor optical transitions of a chosen handedness, the coherent outputs of these chiral nanolasers show a dissymmetry factor as high as 1.1. The small footprint of these lasers are advantageous for applications related to circularly polarized photons in future integrated systems, in contrast to the bulky setup of linearly-polarized lasers and quarter-wave plates.