Monolithically Integrated Circuits with Optical Injection Locking of Ring Lasers for QKD and QPSK Applications

The technique of Optical Injection Locking on integrated ring lasers promises to be a key technology for the improvement of communications bandwidth. However, it is still lacking experimental verification. In this paper, we present two monolithically integrated photonic circuits that experimentally realize optically injection locking of ring lasers. The preliminary circuit characterizations demonstrate the feasibility of these techniques in integrated photonics platforms. These types of circuits pave the way for future applications in Quantum Key Distribution and coherent communication.