Forecasts in deep tech are mostly wishful. So this page separates three things that usually get blurred together: what is already in motion, what we are betting on, and what physics will never allow regardless of funding.
Each horizon depends on the one before it. Nothing in the second is reachable without the hardware in the first, and the third is a clinical and regulatory problem as much as a technical one.
These are not predictions, they are positions. If we are wrong about one, it costs us years. Stating them plainly is how you find out early.
We are betting that 6G research and automotive sensing pull sub-terahertz devices into volume manufacturing, and that we inherit the supply chain. A vertically integrated terahertz company that must fabricate everything itself is a far worse business.
Water absorption is not going to improve. We are betting that reflection-mode coherent reconstruction, frequency agility and learned priors extract clinically useful depth from a signal that classical inversion treats as hopeless.
No craniotomy, no glial scarring against a cortical array, no asking the brain to learn an artificial code — and a signal already in the limb's native language. We are betting the lower-risk path is also the higher-fidelity one.
Closing a forty-year hardware gap is not a venture-timescale problem. We are betting that government programmes fund the components, and that the same components then serve medicine — the path GPS, the internet and modern imaging all took.
Terahertz has a history of overclaiming, and the field carries scar tissue from it. We are betting that publishing our limits attracts the physicists, program managers and clinicians who can actually tell the difference.
A roadmap that cannot fail is not a roadmap. These are the observations that should make you — and us — stop.
If sensitive terahertz detection still requires cooling and single-pixel scanning in ten years, the clinical horizon does not slip — it closes. Every portable application assumes video-rate uncooled imaging.
If computational methods cannot push useful imaging meaningfully past a millimetre in living tissue, terahertz remains a superb dermatology and intraoperative tool and never becomes a general diagnostic one. That is a real business — but it is not this one.
If foreign-body response and micromotion still erode neural signal quality over a handful of years, restoration is a temporary intervention rather than a life returned. Materials, not algorithms, decide this.
Our fascicular mapping claim rests on terahertz sensitivity to myelin and bound water being strong enough to resolve individual fascicles in vivo. If that contrast does not hold outside excised tissue, the deterministic-placement argument collapses.
Four constraints are properties of the universe rather than of our engineering. Any roadmap that quietly assumes these will yield is not worth reading.
Terahertz will always be non-ionising. Photon energy at 1 THz is roughly two thousand times below the threshold to strip an electron. That is permanent, and it is the safety argument that never needs revisiting.
Water will always absorb it. The absorption of liquid water at terahertz frequencies is a material property. Better engineering routes around it; nothing removes it.
Diffraction sets the resolution. At 1 THz the wavelength is 300 µm, so far-field imaging resolves on the order of 150 µm. Sub-wavelength detail requires near-field probing, which only works at surfaces.
No aperture means no direction. A single antenna cannot infer bearing. Position requires many spatially separated radios or genuine array bandwidth — better processing of one link will never produce it.
Two hundred years of electromagnetism produced one band we never learned to use, sitting exactly where biology is most legible and radiation damage is impossible. The hardware to open it is arriving now, mostly funded by people who want faster wireless. What that hardware is pointed at is a choice — and we would rather it were pointed at finding people under rubble, at telling a surgeon where the burn actually ends, and at giving a hand back to someone who can feel it.