On-demand photonic Ising machine with simplified Hamiltonian calculation by phase encoding and intensity detection

Abstract

The photonic Ising machine is a new paradigm of optical computing that takes advantage of the unique properties of light wave propagation, parallel processing, and low-loss transmission. Thus, the process of solving combinatorial optimization problems can be accelerated through photonic/optoelectronic devices, but implementing photonic Ising machines that can solve arbitrary large-scale Ising problems with fast speed remains challenging. In this work, we have proposed and demonstrated the Phase Encoding and Intensity Detection Ising Annealer (PEIDIA) capable of solving arbitrary Ising problems on demand. The PEIDIA employs the heuristic algorithm and requires only one step of optical linear transformation with simplified Hamiltonian calculation by encoding the Ising spins on the phase term of the optical field and performing intensity detection during the solving process. As a proof of principle, several 20 and 30-spin Ising problems have been solved with high ground state probability (≥0.97/0.85 for the 20/30-spin Ising model). Photonic Ising machines exploit the parallelism and high propagation speed of light to solve combinatorial optimization tasks. The authors propose and demonstrate a photonic Ising machine with a fully reconfigurable optical vector-matrix transformation system and a modified algorithm based on simulated annealing, solving 20 and 30-spin Ising problems with high ground state probability.