Optical spectral analysis of the nonlinear dynamics in long-wavelength single-mode VCSELs subject to orthogonal optical injection.

We report an experimental study of the polarization-resolved nonlinear dynamics of a 1550nm single-mode linearly polarized VCSEL when subject to orthogonal optical injection. We measure high-resolution (10 MHz) optical spectra of the linear polarizations and the total power emitted by the VCSEL. Spectra are analyzed together with the simultaneous temporal series of linearly polarized powers. For periodic dynamics, both linear polarizations show spectra with equally spaced peaks with a separation that corresponds to the frequency detuning. As the injected power increases much more peaks are observed with larger (smaller) separation between them when the frequency detuning is positive (negative). For negative values of the frequency detuning, increasing the injected power leads to irregular dynamics that is characterized by optical spectra for both linear polarizations with broad pedestals and much less defined peaks specially for the parallel polarization.The authors acknowledge support from the Ministerio de Ciencia e Innovación under project TEC2009-14581-C02-02