A magnon, the collective excitation of ordered spins, can spontaneously radiate a travelling photon to an open system when decaying to the ground state. However, in contrast to electric dipoles, magnetic dipoles by magnons are more isolated from the environment, limiting their radiation and coherent communication with photons. The recent progresses in strongly coupled magnon-photon system have stimulated the manipulation of magnon radiation via tailoring the photon states. Here, by loading an yttrium iron garnet sphere in a one-dimensional waveguide cavity supporting both the travelling and standing photon modes, we demonstrate a significant magnon radiative damping that is proportional to the local density of photon states (LDOS). By modulating the magnitude and/or polarization of LDOS, we can flexibly tune the photon emission and magnon radiative damping. Our findings provide a way to manipulate photon emission from magnon radiation, which could help harness angular momentum generation, transfer, and storage in magnonics.

当衰减到基态时，磁振子（有序自旋的集体激发）可以自发地将行进的光子辐射到开放系统。但是，与电偶极子相反，磁振子产生的磁偶极子与环境更加隔离，从而限制了它们的辐射以及与光子的相干通信。强耦合磁振子-光子系统的最新进展通过调整光子状态刺激了磁振子辐射的操纵。在这里，通过将钇铁石榴石球加载到同时支持行进和站立光子模式的一维波导腔中，我们证明了显着的磁振子辐射阻尼与光子态的局部密度（LDOS）成正比。通过调制LDOS的大小和/或极化，我们可以灵活地调整光子发射和磁振子的辐射阻尼。我们的发现提供了一种控制来自磁振子辐射的光子发射的方法，这可以帮助利用磁振子中角动量的产生，传递和存储。