Integrated Coherent Ising Machines Based on Self-Phase Modulation in Microring Resonators

We propose an integrated photonic circuit that acts as an optical coherent Ising machine and simulates its performance on the basis of some example problems. In contrast to previous all-optical approaches, the proposed integrated Ising machine does not require an optical parametric oscillator and can, hence, operate at a single wavelength, reducing the overall design complexity. We present a symmetric nonlinear photonic device as the fundamental building block that can use self-phase modulation in two microring resonators to emulate a continuously tunable, symmetrically bistable Ising node. We derive and verify using numerical simulation the key properties of the single Ising node device and the full Ising machine circuit. We estimate the full Ising machine's tolerance to realistic fabrication errors on the basis of randomly sampled example problems, and we discuss which technologies are required to obtain large-scale systems.