Polarization correlations in pulsed VCSELs

Summary form only given. Vertical-cavity surface-emitting lasers (VCSELs) exhibit very interesting physical properties and have great potential for use in optical communications. However, the physical mechanisms that lead to polarization selection in VCSELs are not completely understood, despite much research. We have measured polarization correlations in a pulsed VCSEL. We apply short (3-30 ns) current pulses to the laser and collimate the emitted light with a lens. The laser emission is analyzed into two orthogonal linear polarizations using a polarizing beamsplitter. The two outputs are then detected simultaneously with two photodiodes. Our detection system is calibrated to measure the number of photoelectrons, generated in each detector, which in our experiment accurately reflects the number of incident photons to within our overall detection efficiency.