Located between radio and infrared frequencies, these little-known waves have unique powers that make them particularly useful for a variety of applications, from communications to medical imaging to space exploration.
Terahertz waves and the technologies that harness them are already changing the world, according to Mona Jarahi, professor of electrical and computer engineering at the Samueli School of Engineering at the University of California, Los Angeles, and holder of the Northrop Grumman Endowed Chair.
A hidden corner of the spectrum
The range of the electromagnetic spectrum spans low-frequency radio waves (think:
WLANs and mobile phones) to high frequency gamma rays (such as near nuclear explosions and black holes). At the lower end of the spectrum, radio frequencies enable communication, while higher frequencies such as visible light and infrared light allow us to see and photograph the world around us. Even higher frequencies, such as X-rays, enable detailed medical imaging. However, the range between radio and infrared where THz frequencies exist is still largely underdeveloped due to the inherent difficulty in designing electronics and devices that can operate effectively in this range. “The challenge is not physical limitations, but how to make these types of devices cost-effective, compact and integrated,” said Jarrahi.
These barriers are expected to be broken down in the coming decades.
The Promise of Terahertz Waves. Terahertz waves offer several advantages that make breakthrough technology possible. First, they have a special ability to receive chemical information. Many molecules and chemicals exhibit unique reactions to terahertz waves, which is useful for determining their chemical composition. Waves make up about 98% of all photons, so they can also help reveal valuable information about distant galaxies.
In addition to chemical analysis, THz waves can also penetrate opaque materials, making them ideal for later use in security scanners to provide more detailed images. It also enables higher data rates in communication systems, potentially leading to significantly faster cellular data networks in the future.
Terahertz waves are inherently non-ionizing and non-destructive. In other words, it can be safely used in sensitive areas such as medical imaging and diagnostics. In fact, THz waves are already used in some clinics for burn imaging and quality control in other industries such as automotive, aerospace and pharmaceutical.
Challenges and future of terahertz technology
Despite the unique power of terahertz waves, the technology to harness them is still in its infancy. Most of his current THz devices are large, complex and expensive, limiting their use to laboratories, space missions and factories.
However, it is quite possible that terahertz waves will affect our daily lives in the next few years. As fabrication and material processing techniques advance, it is becoming increasingly possible to scale THz technology in a compact and affordable manner. “The potential applications of THz technology are vast and exciting,” said Jarrahi.
What does it really look like? may be connected.
These future devices will eventually use terahertz waves in the same way spectrometers in space today analyze the composition of planets and galaxies. Normally this process requires low temperatures, but Jarahi’s research group recently discovered a way to do it at room temperature. “We are excited about this because it brings a much cheaper, portable and powerful type of device a lot closer to practical use,” she said.
The transition to THz technology in mobile phones, microprocessors, etc. will probably be gradual, but the impact will be significant. Think of it as one of the next big technology waves.
