Demonstration of electro-optic half-adder using silicon photonic integrated circuits.

We report a silicon photonic integrated circuit which can perform the operation of half-adder based on two cascaded microring resonators (MRRs). PIN diodes embedded around MRRs are employed to achieve the carrier injection modulation. Two electrical pulse sequences representing the two operands of the half-add operation are applied to PIN diodes to modulate two MRRs through the plasma dispersion effect. The final operation results of bitwise Sum and Carry operation are output at two different output ports of the device. Microheaters fabricated on the top of MRRs are employed to compensate two MRRs resonance mismatch caused by the fabrication error through the thermo-optic effect. Addition operation of two bits with the operation speed of 100 Mbps is demonstrated.