Photonic Ising Machine

Liquid-crystal spatial light modulators (LC-SLMs) and Fourier-optical relays enable electronically programmable phase lattices for large-scale spin encoding and optical energy evaluation. We implement a compact photonic Ising machine (PIM) utilizing free-space 4f platforms to support binary or multi-level phase spins, programmable input amplitudes, and precise Fourier-plane detection.

Experimental Capabilities

The spin layer utilizes a reflective, phase-only Meadowlark LC-SLM with crossed polarimetric conditioning to suppress amplitude modulation. A precision rectangular aperture defines an L×L spin grid with uniform telecentric illumination. The module supports binary {0,π} phase encoding for Ising spins and multi-level quantization. An optional amplitude-shaping setup upstream of the SLM imprints spatial weight vectors {J_ij} on the incident field. A diffraction-limited 4f relay images the modulated wavefront to the Fourier plane where spin-dependent intensity distributions form. Scientific cameras (CCD/sCMOS) perform detection with software macro-pixel binning. The system achieves >60 dB dynamic range through flat-fielding, dark subtraction, and exposure bracketing.