Directed Optical Half-Adder Based on Two Cascaded Microring Resonators

We propose and demonstrate a directed optical half-adder based on cascaded microring resonators. Two independent electrical pulse sequences as the two operands are employed to modulate two microring resonators through the thermo-optic effect, respectively. The final operation results of the two operands are output in the form of bit-wise Sum and Carry optical pulse sequences at its two output ports simultaneously. The addition of two bits at 10 kb/s is demonstrated.