Ultimately because of cost and scalability. Photonic components are analog devices not digital so they do not have a “quantum” size that scales with process no

Ultimately because of cost and scalability. Photonic components are analog devices not digital so they do not have a “quantum” size that scales with process node. The size is the same in any node generally. It is possible to make the devices smaller by making them plasmonic but at the expense of loss. Since these are analog signal chains the signal to noise ratio at the end of the lossy device cascade becomes a significant limiting factor. For scalability, the larger the die size the more it costs. The yield also becomes a problem as the die area increases due to random defects. I’d don’t understand the visible light comment since silicon absorbs below 900nm (visible and NIR).