Abstract

Binary optical logic operations (NOR, etc.)¹ are performed using picosecond pump-and-probe techniques at 82 MHz in both bulk GaAs and GaAs-AIGaAs multiple quantum well (MQW) etalons at room temperature. A 0.5 μm thick bulk GaAs crystal having no AIGaAs windows which was sandwiched between 98% reflecting mirrors completely recovered to its original transmission level in 150 ps (Fig. l) despite no intentional doping or damaging. With <30 ps overlap of the input and probe pulses, the total cycle time was <180 ps. The same etalon showed 5:1 contrast in the NOR gate driven by 7 pJ input. A 2×2 array of NOR gates was operated (at 82 MHz) in a MQW etalon having flatter mirrors than our previous etalons. The closest pixel spacing of >12 μm in this array is greater than the maximum displacement (about 10 μm ) at which a single input pulse produces a noticeable effect on a probe pulse. Thus we believe there is no appreciable crosstalk present. A "data diode" (unequal mirror reflectivities allows data to flow in only one direction) was demonstrated. While 5:1 contrast resulted with one side of the etalon facing the input beam, no effect of the input was evident when the other side faced the beam (Fig. 2).

© 1985 Optical Society of America