Why is optical communication more power efficient? The technical explanation is that a photodiode converts the incoming signal to MHz (1,000,000), while an RF antenna keeps the signal at GHz (1,000,000,000). This allows our ASIC to run at MHz, not GHz.
While power consumption is relative to operating frequency this gives us an edge. Another key to success factor is that we use a custom-built ASIC (Application Specific Integrated Circuit) that is tailor-made to our exact needs.
This allows us to avoid compromises that have to be made when using an off-the-shelf SoC (System on Chip).