Demand for fast dynamic reconfiguration has increased since dynamic reconfiguration can accelerate the performance of processors. Dynamic reconfiguration has two important prerequisites: fast reconfiguration and numerous reconfiguration contexts. Unfortunately, fast reconfigurations and numerous contexts share a tradeoff relation on current VLSIs. Therefore, optically reconfigurable gate arrays were developed to resolve this dilemma. Optically reconfigurable gate arrays can realize a large virtual gate count that is much larger than those of current VLSI chips by exploiting the large storage capacity of a holographic memory. Furthermore, optically reconfigurable gate arrays can realize rapid reconfiguration using large bandwidth optical connections between a holographic memory and a programmable gate array VLSI. This paper presents the fastest 317-657 ns reconfiguration demonstration of a 16-context optically reconfigurable gate array architecture.