Investigation of far-field patterns of semiconductor microlasers with an active region based on InGaAs/GaAs quantum well-dots
This paper is the first study of the far-field patterns of semiconductor microlasers with an active region based on In0.4Ga0.6As/GaAs quantum well-dots. A theoretical model describing the far-field radiation pattern is developed. It is shown that in the vertical direction the radiation pattern has a narrow beam divergence (the most of the power is confined to 20 degrees) and is characterized by narrow lobes, the position and number of which are determined by the height of the waveguide relative to the substrate. It is found that in the horizontal direction, each optical mode has its own far-field pattern. A change in the injection current leads to a change in the dominant optical mode and in the far-field pattern. Deviation of the resonator shape from the circular one leads to chaotization of the peripheral modes and generation through more profound WGM-like modes. Reducing the diameter of the resonator leads to a reduction in the number of lobes of the horizontal radiation pattern.