Wave hello to an electromagnetic breakthrough

Yes, this is an article about a kind of electromagnetic wave – but don’t worry, we’re not going to bombard you with physics. It’s just that we’re very excited about this incredible new technology, developed by our scientists in Japan, which generates and transmits terahertz waves through a tiny semiconductor chip. So, indulge us as we geek out. Just a little.

If it’s not something you’ve ever had to think about, let’s start at the beginning. An electromagnetic wave carries energy and, as it travels through space, it doesn’t need anything physical (like air or water) to help it. However, to complicate matters slightly, there are a few different types of waves, which sit on a spectrum. Each kind has different properties, which means they suit different uses.

For example, at one end you have high energy waves, which you would find in things like X-ray machines. These waves can pass through the body at high speed to create a picture of what’s inside. At the opposite end you would find low energy waves, and this might translate into something like a TV or an old-fashioned FM radio, where the waves transmit the broadcasts. It’s important to know that this scale also includes uses which are harmless, right through to the waves which may have some risk for humans because of their levels of radiation.

Nestling in between infrared (your TV remote or motion sensors) and microwaves (self-explanatory!) are terahertz waves. And while this might seem like a fairly unremarkable position to occupy, it’s actually the sweet spot of the electromagnetic spectrum. Taking the best qualities of both, terahertz waves can pass through materials, like a microwave, but can still carry information, like an infrared wave. And this makes them ideal for imaging and communication tasks that cannot involve physical touch (like examining priceless artifacts, or high speed 6G wireless transmission). But here comes the cool part: if these waves are directed at a person or object and the reflected or penetrated waves are captured by a camera, they can form images.

And because they can pass through or be absorbed by materials (without any risk to us) they have potential for all sorts of useful and important purposes. Think security checks at stadiums and festivals, or quality control for everything from cars to drugs. Why? Because if terahertz waves can penetrate clothes without exposing the human body to radiation, they can be safely used in body scanners. And because different kinds of materials absorb or reflect the waves in different ways, they can also be used to analyse and identify materials and objects.

Of course, in science circles this is all well-known stuff. But what is also generally accepted is that terahertz waves are tricky and need a lot of help to be made useful. That is, they require devices to generate them, a way to amplify the waves and antennas to direct and transmit them. The big challenge, so the world can reap the benefits of terahertz waves, was to create a small and powerful way to do all these things at once.

It was an ask. A big ask. But if there’s one thing our R&D scientists live for, it’s a challenge. They focused their attentions on one component, which brought them close to a breakthrough. It was called a Resonant-Tunnelling Diode (RTD) which, very simply, controls the flow of electrical currents. It held a lot of promise as a way to create a small semiconductor chip that worked at room temperature, but there were some problems with how much power it could produce and how efficient it was.

Of course, at our R&D facility we develop thousands of new technologies and eventually we hit the jackpot – an RTD oscillator (to generate the waves), a terahertz antenna (to control their direction) and semiconductor parts (to contain all these ‘ingredients’ so they can work together). Our scientists suspected that by using lots of antennas together they could increase the power, and they were right. By packing an astonishing 36 minuscule antennas on an 8mm x 10mm semiconductor chip they were able to make this incredible breakthrough: a tiny chip capable of generating strong terahertz waves. It took twenty years but, boy, it was worth waiting for.

So, what happened next? Imagine a crack team of incredible scientists who work for the world’s most innovative imaging company, working in a room with a new, tiny and wonderfully powerful chip…

It doesn’t take a genius to figure out that they invented a prototype terahertz camera. It captures terahertz waves using lenses and sensors and they’ve already demonstrated how ‘terahertz imaging’ can detect objects hidden inside people’s clothing – from several metres. They’ve even used it to spot the difference between types of liquid (potentially game-changing at airports but has huge implications if used in industry). And their potential for a 6G world has sparked a great deal of interest alone.

So, can you see now why we’re so excited? Because for our R&D geniuses, this is just the beginning.

If you want to delve deeper into this amazing tech, head to Canon Global Technology, where you’ll find a full explainer of our new semiconductor terahertz source.