He taught radio waves to see through clothing, then built a company so the rest of us could look.
Point a surveillance camera at a crowd and it sees coats, bags, and the weather. Point Nathan Monroe's sensor at the same crowd and it sees the outline of a pistol under a jacket, the shape of a blade in a backpack, the contraband tucked inside a sealed box. Same physics that runs an airport scanner. None of the airport.
Monroe is the co-founder and CEO of Cambridge Terahertz, an MIT spinout that turns a sliver of the radio spectrum into 3D vision. The pitch is almost rude in its simplicity: take the room-sized machine you shuffle through at the gate, compress it onto a chip, and let it sit quietly on a wall like any other camera. Then let an AI - and only the AI - look at the picture.
The technology is exotic. The reason he built it is not. Monroe grew up in Florida, and his high school lived through a shooting in which the principal was killed. That fact is the load-bearing wall under everything he has built since. He spent more than a decade at MIT making the physics work, and now he spends his days arguing that detecting a concealed weapon should be as ordinary, and as invisible, as a security camera.
We believe even one death from a concealed weapon is too many.Cambridge Terahertz, founding principle
See the invisible. Detect weapons. Save lives.
Terahertz waves sit in the awkward, useful gap between microwaves and infrared light. They pass through fabric, paper, plastic, and ceramic, and they bounce off metal and skin. For decades the equipment to harness them was the size of a refrigerator and priced like one too. That is the wall Monroe spent his PhD knocking down.
As a researcher in MIT's Terahertz Integrated Electronics group, he demonstrated one of the highest-performance terahertz phased antenna arrays on record - on the order of 10,000 antennas - and built the first THz circuits in Intel's 22nm FinFET process. The trick was using ordinary, scalable CMOS, the same manufacturing that makes everyday chips cheap. The result: airport-scanner capability in a package smaller than a toaster.
FIG. 1 - Terahertz: long enough to pass through cloth, short enough to draw a shape.
Emit. Safe, non-ionizing radio waves - not X-rays - sweep across a person or package.
Read. The waves pass through clothing and materials and reflect off metal, plastics, and skin, returning a detailed 3D signal.
Interpret. AI reads the raw image in real time and flags the shape of a weapon - a guard never sees the body underneath.
Deploy. The whole thing mounts discreetly, like a camera, so screening is invisible instead of a checkpoint.
Just like you deploy surveillance cameras to see what is visible, you can now deploy our terahertz sensor system to see the invisible.
The founding mythology of Cambridge Terahertz is unfashionably literal: a prototype, a workbench, and a garage near MIT. From there the team grew into one stitched together from Microsoft, Amazon, Analog Devices, Bell Labs, Boston Consulting Group, and the U.S. Army.
The mission has two origin points, both public, both heavy: a school shooting and the Boston Marathon bombing. Monroe doesn't dress them up. They are why a man who could have stayed in academia chasing record-breaking arrays decided instead to ship a product.
Nathan is the best hardware person I know.A portfolio-company CTO, via Felicis
The terahertz and chip mind. Ex-Microsoft Kinect. Six patents and a record-setting array to his name.
20+ years in the chip industry, 10 patents. Pairs Stanford silicon depth with Monroe's MIT terahertz.
25+ years in product, former CEO and director roles around Cisco and Juniper, 17 patents.
Privacy is non-negotiable. Only the AI sees the raw image.Cambridge Terahertz, on how the system is designed
Before weapons detection, he helped ship sensor tech inside the Xbox Kinect. He has a habit of making weird sensors feel normal.
The core technology compresses equipment once the size of a refrigerator into a device smaller than a toaster.
It uses safe, non-ionizing radio waves - not X-rays - to see through clothing, paper, plastic and ceramics.
By design, no human guard sees the raw scan. Only the AI interprets the body underneath.
His co-founder holds a Stanford PhD - an MIT-plus-Stanford terahertz brain trust in one company.
The same sensor that finds weapons can spot return fraud by seeing inside an unopened package - which is what caught Amazon's eye.
Monroe's wager is that weapons screening becomes ubiquitous by becoming invisible. No checkpoints, no lines, no taking off your shoes. A sensor on a wall in a school, a venue, a transit station, doing the work quietly and handing only the answer - not the image - to the people who need it. The funding, the FCC license, the five government contracts, the 300-plus demos: all of it is in service of one stubborn idea about what public safety should feel like, which is to say, like nothing at all.