The results of two electro-optical implementations of the alternating projection neural network (APNN) are presented. Both configurations use optical matrix-vector multipliers with electronic feedback, but different spatial light modulators are employed. The first implementation is passive, employing a photographic transparency that intensity-modulates the incident incoherent light. In the second implementation, two spatial light modulators actively modulate the light, permitting real-time updating of the interconnection matrix elements. To the authors' knowledge, the implementations described are the first of the APNN.