Optoelectronic flexible-function logic gate using monostable-bistable transition of serially connected resonant tunneling transistors

A novel optoelectronic resonant tunneling logic gate, OE MOBILE, is propose d and its basic logic functions such as NOT, NOR, NAND, OR, and AND are con firmed for optical inputs. The fundamental idea is to use optical inputs to determine the logic level of the gate which consists of two serially conne cted resonant tunneling transistors (RTTs) with a p(+)/n-junction gate. The OE MOBILE is operated by oscillating bias voltage to employ monostable-bis table transition. At the time when the transition occurs, the optical input s are applied by illuminating the RTTs to control their peak currents and c onsequently to determine the output logic levels. The pourer of an optical input for logic operations is as small as 5 mu W owing to the operation bas ed on monostable-bistable transition. It should be pointed out that the fun ctions of an OE MOBILE can be changed between NOR and NAND by changing the control terminal voltage.