Airbus Group Innovations, together with seven TeraTOP consortium partners, has developed a new on-chip terahertz camera. Terahertz frequencies - which correspond to 300 gigahertz to 10 terahertz - occupy a section of the electromagnetic spectrum between the microwave and the optical. When used for security screening applications, for example, terahertz imagers provide higher-resolution images than existing millimetre wave imagers.

But while the use of other parts of the electromagnetic spectrum - from X-rays to millimetre waves - is ubiquitous in imaging technology, the terahertz frequency remains mostly underutilised despite decades of research. That's because existing applications tend to have complex manufacturing processes and require extensive cooling during operation - resulting in prohibitively high production and operating costs and correspondingly low market demand. The new camera is based on technology that has the potential to significantly lower production costs and enable future mass production of terahertz cameras and imagers - a big step forward in advancing the commercial use of terahertz technology for imaging in the future.

Key to TeraTOP's research was determining an appropriate strategy for developing and producing a terahertz imaging device with complementary metal oxide semiconductor (CMOS) technology. As CMOS technology is widely used in computer processors and mobile phone camera chips, it promises the reduction of production costs as well as improvements in performance. The new chip-integrated camera (0.5 -1.5 THz) is expected to expand the fields of application, and uses a completely new type of terahertz sensor that enables operation at room temperature.

This gives it a clear advantage over terahertz sensors that normally require expensive cryogenic cooling to temperatures below minus 200°C to perform well. The blend of advanced technologies for this new camera led to improvements in thermal sensitivity and high-level integration of terahertz components. A demonstrator, comprising a 24x24 focal-plane-array (FPA) of detectors and readout circuitry operating in video imaging mode, was built, and its full functionality successfully tested.

The current camera design is suited for active terahertz imaging.