A silicon photonic chip includes a silicon on insulator wafer and an electro-optical device on the silicon on insulator wafer. The electro-optical device is a lateral current injection electro-optical device that includes a slab having a pair of structured doped layers of III-V semiconductor materials arranged side-by-side in the slab, the pair of structured doped layers includes an n-doped layer and a p-doped layer, each of the p-doped layer and the n-doped layer is configured as a two-dimensional photonic crystal. A separation section extends between the pair of structured doped layers, the separation section fully separates the p-doped layer from the n-doped layer. The separation section includes current blocking trenches, and an active region of III-V semiconductor gain materials between the current blocking trenches that form a photonic crystal cavity.