Direct modulation of microcavity emission via local perturbation

Next-generation integrated photonic circuits (PCs) require the combination of on-chip coherent light sources and modulators to increase the integration density and reduce the energy consumption. While significant advances have been accomplished in direct laser modulation and channeling the modulated emissions into waveguides, there is still an enormous challenge in distributing the signals to their designed ends. Here we show that the outputs from microcavities can be directly modulated by local perturbations. We demonstrate this concept in a waveguides connected quadruple cavity, where the generated signals can be optionally distributed to one or multiple designed waveguides by slightly modulating the refractive index on the order of 0.01. This concept should help the advances of high-density on-chip photonic circuits.