Spatial light modulators are currently used to shape wavefronts at micron scales for various applications such as lighting, beam steering or digital holography. High-resolution holographic displays require the smallest pixels. Today, liquid crystal on silicon (LCOS) technology does not allow pixel pitch to be reduced to less than 1 μm, and metasurface technology still does not allow independent control of each meta-atom in the visible range. With this in mind, we turned our attention to a new all-optical addressing principle based on crossed silicon waveguides coupled to plasmonic nanoparticles (NPs), themselves interacting with a phase-change material. We will describe the various steps involved in demonstrating this system, with the aim of achieving a high-resolution, all-optical spatial light modulator.