Demands for fast dynamic reconfiguration for programmable devices have increased because the fast dynamic reconfiguration can increase the number of functions on a gate array. This paper presents a proposal of a novel optically differential reconfigurable gate array architecture with a microelectromechanical system (MEMS) mirror array that enables high-speed reconfiguration by exploiting large-bandwidth optical connections between the MEMS mirror array and a programmable gate array. The MEMS mirror array is used as a holographic memory. Four configuration contexts can be programmed electrically and dynamically onto the MEMS mirror array as holographic memory information. A configuration procedure is executed by switching of both a laser array and a MEMS mirror array. This experiment has demonstrated a four-context 9 ns microelectromechanical reconfiguration for a programmable gate array.