Terahertz Technology: Unlocking New Dimensions in Industrial Measurement and Quality Control

The main constraint on industrial terahertz adoption is not physics, but people. A deviation of a few microns in a hidden plastic layer can be the difference between a product lasting six months or six days. Terahertz technology can see that deviation on a moving production line. The 2023 terahertz science and technology roadmap is therefore a hiring signal for a specific class of industrial physicist: one who can make invisible material properties visible in a factory.

The technology is moving from the research bench to the production line. It is not just another industrial sensor. Its photons are non-ionising, unlike X-rays. It is non-contact, unlike ultrasound. This combination allows it to measure hidden layers inside opaque plastic or find voids in composite materials in real time. The physics is understood. The people who can translate that physics into a reliable industrial process are scarce. The problem is not the sensor; it is the system, and the system includes the human.

What is driving the industrial adoption of terahertz technology?

The driver is the need for better data in quality control. Terahertz radiation sits between microwave and infrared frequencies. It penetrates materials like plastics and ceramics that are opaque to visible light, but is strongly absorbed by water. This provides a way to conduct 2D and 3D imaging and precise point measurements without destroying a product.

Companies use this to reduce waste. LUNA’s Terametrix division, for example, uses THz systems for non-destructive measurement, as detailed in Plastics Engineering. Their systems analyse the discrete layers within multi-layer bottles. For a beverage company, ensuring every layer—oxygen barrier, structural layer, moisture barrier—meets its micron-level specification determines shelf life. Terahertz verifies these hidden structures on the production line, not just in a lab by destroying samples. This shifts quality control from a retrospective audit to a real-time process parameter.

Helmut Fischer uses the same method to measure coating thickness. In automotive manufacturing, the uniformity of a polymer on a carbon-fibre component determines its resistance to weather. In aerospace, a coating’s thickness can affect a component’s thermal properties or radar signature. THz offers a precise, non-contact way to measure these coatings.

These applications allow manufacturers to quantify features that were previously invisible in a high-throughput environment. Research organisations like the Fraunhofer-Gesellschaft classify THz measurement as a key non-destructive testing method. The value is not in the terahertz wave, but in the process control data it unlocks.

Why is terahertz not yet a mainstream tool?

A terahertz system is not as common as a machine vision camera because it is harder to implement. The main obstacle has been the “terahertz gap”: the difficulty of generating and detecting the radiation efficiently and reliably at a reasonable cost. The frequency is too high for conventional electronics and too low for conventional photonics. Technologies like quantum cascade lasers and photoconductive antennas have improved generation, but the systems remain complex.

Implementing a THz system is not a plug-and-play task. A reliable measurement requires expertise in photonics to align optics, high-frequency electronics to drive the emitter, and signal processing to filter noise. Interpreting the data requires understanding THz spectroscopy. A small change in ambient humidity can corrupt a measurement, as water vapour is a strong THz absorber. This requires complex calibration to compensate for environmental factors.

The reality of the market is governed by system engineering. An industrial THz sensor must operate for millions of cycles amidst the vibration, temperature fluctuations, dust, and electromagnetic noise of a factory. The challenge of engineering a system to withstand this environment is as significant as the underlying physics. As a result, adoption remains concentrated in high-value sectors like aerospace, pharmaceuticals, and semiconductor manufacturing, where the cost of a product failure justifies the investment in specialised equipment and the people needed to run it.

Where is the evidence for terahertz’s impact?

The evidence is in the strategic focus of research institutions and the breadth of emerging applications. This is about more than measuring plastic and paint.

The Oxford Terahertz Photonics Group, including researchers like Dr. Kun Peng, projects that THz radiation will be central to future 6G wireless communications. This points to a future where the same technology inspecting a car part could enable data transfer for autonomous vehicles. This dual use in communications and sensing accelerates development and expands the talent pool. A breakthrough in communications hardware can be adapted for industrial sensing.

The science is also advancing from passive measurement to active manipulation. Researchers have used THz light pulses to control quantum states in materials like iron phosphorus trisulphide (FePS₃). This work shows THz is not just a passive tool for observing a material, but an active one for changing a material’s properties. This suggests THz systems could be used for in-line manufacturing, such as tuning a material’s electronic properties during its creation.

The application space is widening. In security, THz can detect non-metallic threats. In life sciences, its sensitivity to water is being explored for medical diagnostics, such as identifying cancerous tissue by its different water content. In agriculture, it could assess the water stress of crops. Each field relies on the same core competencies. This breadth indicates a platform technology, not a niche tool.

What does this mean for talent and hiring?

The primary consequence is a talent bottleneck. The ideal candidate for a senior role in applied terahertz technology needs a skillset that traditional career paths rarely produce. They are four roles in one: a physicist who understands light-matter interaction; an optical engineer who can design a system for a factory floor; a manufacturing engineer who understands cycle times; and a data scientist who can translate a noisy waveform into a pass/fail signal.

This creates competition for a small pool of qualified people. This talent market exists in the shadow of more visible sectors. Markets track quantum computing firms like Rigetti Computing and D-Wave, or the partnership between Silicon Quantum Computing and cryogenics specialist Bluefors. The demand for THz specialists grows more quietly. For these experts, the work is about eliminating defects per million, not chasing qubits. A parallel exists in security, where government bodies like CISA focus on post-quantum cryptography with firms like ZeroRISC, while a need grows for experts who can secure industrial processes through better physical measurement.

Companies hiring in this space cannot simply post a job advertisement for a “Terahertz Engineer”. They must build this talent by funding PhDs and creating partnerships with academic groups like the one at Oxford. They are not buying a piece of equipment; they are building an internal capability embodied in people.

The Quantum People verdict

Terahertz technology is a proven tool for industrial quality control. Its widespread adoption is gated by human expertise, not hardware availability. The technology is moving out of the lab, but the mindset required to deploy it successfully—a blend of physics and factory-floor engineering—is rare.

The most successful companies will treat talent as the critical component of their terahertz systems. They will invest in the multi-disciplinary teams required to translate a faint electromagnetic signal into a manufacturing decision. Value is created not when the emitter is switched on, but when a skilled team uses its data to make a process more reliable.

The challenge is not finding a terahertz source, but finding the person who knows what to do with it.

Sources

• PDF Which technology should be used to see through matter: Terahertz …
• Non-contact ultrasound imaging based on sub-terahertz …
• Terahertz radiation – Wikipedia
• Terahertz Radiation Sources for Imaging and Sensing Applications
• Strong Terahertz Radiation from a Liquid-Water Line – APS Journals
• Non-Destructive Testing with Terahertz Technology