Data patterns are shown to affect the far field distribution of vertical cavity surface emitting lasers (VCSELs). Two data
patterns with different frequency content resulted in different
beam profile distributions even though both patterns had 50% duty
cycles resulting in the same thermal dissipation. The effect of
gain switching and varying high and low drive levels was also
investigated. Angle dependent waveforms displayed overshoot on
axis and undershoot off axis. The potential impact of pattern
dependent launch conditions is discussed.