Frequency response of an on-chip multi-wavelength laser subject to optical injection with single sideband modulation

In this report, we experimentally analyze the effect of optical injection of a signal with a single-sideband (SSB) modulation on a multi-wavelength laser (MWL) integrated on a photonic integrated circuit. The optical injection of an SSB modulation into the MWL leads to spectral multiplication of the signal around the un-injected modes of the MWL. This multiplication arises from the modulation of the carrier density inside the cavity and the strong nonlinear coupling between different modes of the MWL. We report an asymmetric power evolution of the generated sidebands around the injected and un-injected modes of the MWL while the modulation frequency is swept. The power and modulation bandwidth of the signal emerging around the injected and un-injected modes strongly depend on the position of the cavity resonance frequency of the injected mode, which can be tailored by adjusting the injection strength and the detuning of the injected signal.