Traveling-wave model of coherent Ising machine based on fiber loop with pulse-pumped phase-sensitive amplifier

Abstract

A coherent Ising machine (CIM) is an optical system that physically solves combinatorial optimization problems based on the Ising model. This paper presents an analytical model describing the operation of a CIM using a long fiber loop with a phase-sensitive amplifier. Instead of the conventional analytical model based on the mean-field approximation in a cavity, a traveling-wave model, which traces the state evolution of each pulse circulating along the loop, was applied. A difference equation for the state of a pulse moving around the loop was derived, and simulations were performed. These results reflect the CIM operation reasonably well.