Multimode dynamics in a semiconductor laser with optical injection

An experimental study of multimode dynamics in a two-mode semiconductor laser with optical injection is presented. The device we consider is a specially engineered two-colour Fabry-Perot laser diode [Eblana Photonics] with a large (THz) primary mode spacing. At a fixed injected power level, we vary the detuning of the injected field from the long wavelength mode of the device. The optical spectra of the two primary modes are shown as a function of the frequency detuning of the injected signal. We have adapted the well known model of a single mode laser with optical injection to account for the second lasing mode. We also show that chaotic dynamics of the injected mode can be accompanied by on-off intermittency, where we find irregular switching of the uninjected mode that is associated with the transverse instability of the dynamics in the single mode manifold.