Programmable Optical Digital Logic Computing Array Using Dual-Drive Mach-Zehnder Modulators

This paper proposes and investigates a scheme of Programmable Optical Digital Logic Computing Array (PODLCA) which mainly consists of basic blocks using dual-drive Mach-Zehnder modulators (DD-MZM). By adjusting the parameters of DD-MZM, full coverage of 24 types of logic operations can be implemented, making the Programmable Optical Digital Logic Computing Block (PODLCB) highly reconfigurable. Optimization of each logic operation is achieved through systematic adjustment of the PODCLB to obtain an output optical signal with maximum extinction ratio. Experimental implementation of AND, OR, NAND, NOR, XNOR, and XOR logic operations at a speed of 32 Gb/s is successfully realized using one PODLCB with clear observation of eye diagrams and high extinction ratios. According to the frequency response of the system, the PODLCB demonstrates significant potential for achieving high operating speeds, with the primary limiting factor being the bandwidths of the modulator and photodetector. Furthermore, various complex optical digital logic computing operations can be achieved through different combinations of PODLCBs, validating its high scalability. The proposed scheme features advantages in terms of reconfigurability, operating speed, signal quality and scalability, making it a promising solution for large scale programmable optical digital logic arrays.