Reconfigurable nonreciprocal light transmissions for multiband signals

In practical signal processing and optical computing, multiple signals in different frequency bands usually require nonreciprocal transmission. However, to date, most proposed nonreciprocal systems based on nonlinear resonators only support a single working band. Here, we demonstrate that nonreciprocal light transmissions can be realized in multiple distinct spectral bands, solely via a single nonlinear multimode nanocavity triggered by a control pulse. More importantly, our results further show that the multiband nonreciprocal light transmission is reconfigurable, with high contrasts and reasonably broad per-band bandwidths. The underlying physical mechanism is revealed. The approach presented here is promising in the fields of optical signal processing, quantum computing, optical routers, and rectifiers.