An optical AND gate is provided that includes an optical thyristor configured to receive first and second digital optical signal inputs. The optical AND gate further includes control circuitry operably coupled to terminals of said optical thyristor. The control circuitry is configured to control switching operation of said optical thyristor in response to the ON/OFF states of the first and second digital optical signal inputs such that the optical thyristor produces a digital output signal that represents the AND function of the first and second digital optical signal inputs.In another aspect, an AND gate is provided that includes a thyristor and control circuitry operably coupled to terminals of the thyristor. The control circuitry is configured to receive first and second digital electrical signal inputs and control switching operation of the thyristor in response to the levels of the first and second digital electrical signal inputs such that the thyristor produces a digital output signal that represents the AND function of the first and second digital electrical signal inputs.