In this paper the interference pattern of optical vortices was observed. A laser diode centered at 800nm was used in conjunction with a spatial light modulator to produce optical vortices of whole integer and fractional charge values. A shear plate was then used to produce an interference pattern. This interference pattern was characterized in order to determine the topological charge of the vortex. In addition to the experimental work in the laboratory, the shear plate, optical vortices, and resulting fringe patterns were modeled using Zemax optical modeling software. The modeled results were compared to the experimental results.