VCSEL mode and polarization control by an elliptic dielectric mode filter

In this paper, we demonstrate the effectiveness of polarization mode control in vertical-cavity surface-emitting lasers (VCSELs) with integrated elliptic dielectric mode filters. The single-mode single-polarization laser operation is obtained by an irregularly shaped oval dielectric mode filter, aimed at cost-effective mass production. The orthogonal polarization suppression ratio was measured to be 16.7 dB, and the side-mode suppression ratio exceeded 30 dB. A single fundamental mode power of 0.55 mW was achieved at a bias current of 4 mA. We compared the spectra and near-field intensities of the dielectric mode filter VCSEL with a reference device. The comparison clearly indicates the effectiveness of our dielectric mode filter in controlling the transverse- and polarization-mode properties of VCSELs.