Far-field control of vertical cavity surface emitting lasers

The far-field control of vertical-cavity surface-emitting lasers (VCSELs) has been studied experimentally and theoretically. The experimental results show that the window and the gain-guided area radiuses of VCSELs strongly influence laser far-field distributions and beam characteristics; for VCSELs with small window radius w = 2.5 ??m, only one dominant lobe has been observed in the far-field profiles, even though injected current was increased up to 2 Ith; and the smaller the ratio of the window radius to the gain-guided area radius, the larger is the far-field divergence. To understand the experimental results, we have also performed a calculation using a method of finding self-consistent solutions for the carrier diffusion and the optical field equations. The calculated results are in good agreement with those of the experiments.EI