Computing using light not transistors

If you send a beam of light through a bit of paint, you will get a mathematical transformation of the signal you sent in - for free! Now, scale that idea up, and you’ve got a very fast and energy efficient method of computation called optical computing - let’s dig in..

Optical computing is a completely different paradigm to solve the same problem - swapping electrons for photons, promising blazing speed and profound energy efficiency. As silicon-based computing strains under the demands of AI and data centers, optical computing promises an interesting alternative.

Unlike conventional systems, where electrons trudge through silicon transistors, optical computing uses light - lasers, lenses, and photonic circuits - to encode and process data. Photons move at the speed of light, slashing latency, and can carry multiple signals at once using different wavelengths or polarizations. This makes them perfect for parallel tasks like AI training.

The energy argument is even stronger: photonic systems bypass the resistive heat that throttles electronic chips, potentially slashing power use by orders of magnitude. With data centers now consuming over 1% of global electricity, this efficiency is a potential game changer.

The challenges, though, are steep. With semiconductors, we have decades of innovation, and infrastructure for classical computing. However, melding photonic components with existing silicon infrastructure is like fitting a jet engine into a horse-drawn cart. Crafting reliable, cost-effective optical transistors and memory systems is still a research frontier, far from mass production. Converting data between optical and electronic realms adds latency, dulling the speed advantage. The supply chain for photonic chips is embryonic, and manipulating light at nanoscale demands exacting precision. These aren’t mere tweaks - they call for a fundamental overhaul of how we design and build computers.

If there is sufficient momentum around this technology, optical computing could be a bold leap that could drive our AI future. It demands we reimagine computation from the photon up, balancing audacious potential with hard-nosed practicality.

What do you think? Will optical computing light the way forward?

Image credit: Nanophotonics (2025). DOI: 10.1515/nanoph-2024-0513