We theoretically discuss the input–output characteristics of the cascaded magnon-photon system by focusing on the slow light effect caused by positive group delay. When two identical magnon-photon systems are cascaded, compared with the single cavity system, the bandwidth of the whole system is wider, but the group delay is smaller. The change of the group delay is different from that of the general linear system. Moreover, by changing the cavity length of the two microwave cavities, the system is slightly mismatched and the group delay could obviously increase. The slow light effect could be controlled by relative cavity length. The slow light effect of the mismatched double cavity system is more sensitive to external magnetic field than that of the single cavity system. The results provide a way to manipulate the transmission rate in optical information networks and a new view about the interconnection of microwave cavities.

中文翻译：

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级联磁光子系统中相对腔长控制的慢光

我们通过关注正群延迟引起的慢光效应，从理论上讨论级联磁光子系统的输入输出特性。当将两个相同的磁光子系统级联时，与单腔系统相比，整个系统的带宽更宽，但群时延更小。群延迟的变化不同于一般线性系统的变化。而且，通过改变两个微波腔的腔长，系统略有失配，群时延明显增加。慢光效果可以通过相对腔长度来控制。与单腔系统相比，不匹配的双腔系统的慢光效应对外部磁场更敏感。