16-channel Photonic Solver for Optimization Problems on a Silicon Chip

TL;DR

This paper presents a 16-channel silicon photonic chip that accelerates solving quadratic optimization problems using optical vector-matrix multiplication, achieving high success rates and a computing speed of around 2 TFLOP/s.

Contribution

The work introduces the largest on-chip programmable photonic solver for QUBO problems, combining a silicon photonic chip with electronic heuristics for fast optimization.

Findings

Successfully solved two 16-dimensional QUBO problems with high probability

Achieved a photonic OVMM speed of approximately 2 TFLOP/s

Reported the largest scale programmable on-chip photonic solver to date

Abstract

In this article, we proposed a programmable 16-channel photonic solver for quadratic unconstrained binary optimization (QUBO) problems. The solver is based on a hybrid optoelectronic scheme including a photonic chip and the corresponding electronic driving circuit. The photonic chip is fabricated on silicon on insulator (SOI) substrate and integrates high-speed electro-optic modulators, thermo-optic phase shifters and photodetectors to conduct the 16-dimensional optical vector-matrix multiplication (OVMM). Due to the parallel and low latency propagation of lightwave, the calculation of the QUBO cost function can be accelerated. Besides, the electronic processor is employed to run the heuristic algorithm to search the optimal solution. In the experiment, two 16-dimensional randomly generated QUBO problems are solved with high successful probabilities. To our knowledge, it is the largest scale of programmable and on-chip photonic solver ever reported. Moreover, the computing speed of the OVMM on photonic chip is ~2 TFLOP/s. It shows the potential of fast solving such optimization problems with integrated photonic systems.