[20p-A202-1~19] 3.1 Basic optics and frontier of optics (merged with formerly 3.2 Equipment optics and materials)

▲ [20p-A202-17] Numerical Analysis of Unidirectional Lasing Conditions in Ring Resonators towards Active Skyrmion Lasers

〇(D)ZHIWEI DAI¹, WENBO LIN¹, SATOSHI IWAMOTO^1,2 (1.RCAST, Univ. of Tokyo, 2.IIS, Univ. of Tokyo)

Keywords:unidirectional lasing, optical skyrmion, ring resonator

Light with various topological structures have recently attracted much attention with their novel properties and applications, optical skyrmions being one of them. Our group has proposed and experimentally demonstrated the generation of optical skyrmion beams on nanophotonic platforms, using a passive ring resonator. An active optical skyrmion source will further increase reliability and compactness, but the key issue lies in the generation of beams with non-zero orbital angular momentum, which requires unidirectional lasing in ring resonators. One potential solution uses an S-shaped coupler. Here, we numerically analyze the condition of unidirectional lasing in a ring resonator equipped with an S-shaped coupler using rate equations including gain saturation effect. The result indicates that cross-saturation between degenerate modes is key to unidirectional lasing.