  Ising machines based on analog systems have the potential of acceleration in
solving ubiquitous combinatorial optimization problems. Although some
artificial spins to support large-scale Ising machine is reported, e.g.
superconducting qubits in quantum annealers and short optical pulses in
coherent Ising machines, the spin coherence is fragile due to the ultra-low
equivalent temperature or optical phase sensitivity. In this paper, we propose
to use short microwave pulses generated from an optoelectronic parametric
oscillator as the spins to implement the Ising machine with large scale and
also high coherence under room temperature. The proposed machine supports
10,000 spins, and the high coherence leads to accurate computation. Moreover,
the Ising machine is highly compatible with high-speed electronic devices for
programmability, paving a low-cost, accurate, and easy-to-implement way toward
to solve real-world optimization problems.
