ROHM Offers the Industry’s Smallest* Terahertz Wave Oscillation and Detection Devices

　　ROHM has begun offering samples of the industry’s smallest* terahertz (THz) wave oscillation and detection devices utilizing semiconductor elements known as Resonant Tunneling Diodes (RTDs). Terahertz waves are anticipated to be applied to non-destructive testing, imaging, and sensing in the medical and healthcare sectors, as well as potentially future ultra-fast communication technologies. Providing these devices contributes to the advancement of terahertz wave applications.

　　ROHM has developed a 0.5mm × 0.5mm RTD chip for terahertz wave generation and detection, capable of oscillating and detecting terahertz waves at a frequency of 320GHz (typ.) with an output power ranging from 10 to 20µW. ROHM will begin offering samples of this RTD element mounted in a PLCC package (4.0mm × 4.3mm) commonly used for LEDs. With an extremely compact size, typically than one-thousandth that of conventional oscillators, this innovation enables easy development of terahertz wave applications, even in space-constrained environments.

　　By positioning the antenna surfaces of the oscillation and detection devices facing each other 10mm apart, a dynamic range of 40dB (typ.) can be achieved. Both oscillator and detector maintain a drive power consumption of 10mW (typ.), while their ability to oscillate and detect terahertz waves at room temperature eliminates the need for cooling equipment required with some conventional methods. These compact, power-saving devices are almost unaffected by the operating environment, enabling use in a wide range of applications.

　　ROHM offers samples of terahertz wave oscillation and detection devices at a sample price of $990.0/unit (excluding tax), which is less than one-tenth the price of conventional devices. ROHM also provides evaluation kits that include an evaluation board and other components, allowing users to easily integrate the devices into a research and development environment. For more information, please contact a sales representative or visit the contact page on ROHM’s website. The sale of sample products and evaluation kits requires the prior signing of a non-disclosure agreement (NDA) with ROHM.

　　Professor Safumi Suzuki, Laboratory for Future Interdisciplinary Research of Science and Technology, Institute of Integrated Research, Institute of Science Tokyo

      “Terahertz waves are expected to be applied to various fields such as imaging, sensing, and wireless communications due to their excellent characteristics and high degree of safety. However, research and development for commercialization has traditionally required large-scale equipment and substantial costs.

　　In this context, the RTD terahertz wave device - developed through years of collaborative research with ROHM - is an ultra-small 4.0mm × 4.3mm device that challenges conventional norms while featuring astonishingly low power consumption and implementation costs. With the launch of device samples, we anticipate that many private companies and research institutions will begin exploring terahertz wave research.

　　We hope that the use of terahertz waves in various fields will lead to the creation of new applications with functions that were previously difficult to achieve. Going forward, we will continue to contribute to society through the development of terahertz wave devices in partnership with ROHM.”

　　Ken Nakahara, General Manager of Center, ROHM Research & Development Center, ROHM Co., Ltd.

      “The terahertz (THz) R&D team and I are very excited and proud to have reached the point where we can bring this technology to market. We have dedicated ourselves to THz devices for about 15 years; the journey has not been easy. We gathered the forces of industry, academia, and government along the way, and have successfully established the position that ROHM holds today.

　　The team understands that this announcement is just a small step toward the commercialization of THz technology, but at the same time, it is a giant leap for us. We believe that this small beginning will grow big and contribute to the well-being of our society.”

　　Background and Development Summary

        Occupying the frequency region between radio waves and light, terahertz waves exhibit a variety of distinctive characteristics, including excellent permeability similar to radio waves, straight-line propagation akin to laser beams, and unique absorption properties for materials such as polymers. As such, they are expected to be utilized for non-destructive testing, imaging of humans and materials without the use of dangerous radiation, high-speed communication as an alternative to conventional wireless transmission, and high-resolution radar sensing. However, conventional methods often require large equipment sizes and high implementation costs often ranging from tens of thousands to hundreds of thousands of dollars, making it challenging for private companies to actively pursue research or commercialize in the field of practical terahertz applications.

　　Since the late 2000s, ROHM has engaged in joint research with numerous universities and research institutes, such as the Institute of Science Tokyo and Osaka University. The key aim: developing terahertz wave oscillation and detection devices using RTD technology. ROHM is also involved in several consortia, including national projects (government R&D initiatives) sponsored by the Ministry of Internal Affairs and Communications (MIC), the National Institute of Information and Communications Technology (NICT), and the Japan Science and Technology Agency (JST), as well as the XG Mobile Promotion Forum and the Terahertz System Application Promotion Council. ROHM will continue to focus on device development while contributing to the early industrialization and social integration of terahertz technology.

　　Professor Safumi Suzuki Profile

        Doctor of Engineering, Professor at the Laboratory for Future Interdisciplinary Research of Science and Technology, Institute of Integrated Research, Institute of Science Tokyo. His research targets the development of terahertz wave devices using resonant tunneling diodes (RTDs).

　　• Career

　　March 2009　: Completed a doctoral program at the Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology

　　April 2009　: Assistant Professor, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology

　　April 2014　: Associate Professor, Faculty of Engineering, Tokyo Institute of Technology

　　August 2024　: Professor, Laboratory for Future Interdisciplinary Research of Science and Technology, Institute of Innovative Research, Tokyo Institute of Technology

　　October 2024　: Professor, Laboratory for Future Interdisciplinary Research of Science and Technology, Institute of Integrated Research, Institute of Science Tokyo

　　Terminology

         Resonant Tunneling Diode (RTD)

　　A terahertz wave light source that uses semiconductor elements to provide advantages such as small size, low power consumption, and the ability to oscillate at room temperature. Following extensive research and development with various universities and research institutions, ROHM has successfully achieved in-house production of RTD devices capable of efficient terahertz wave oscillation and detection.

　　PLCC

　　Short for Plastic Leaded Chip Carrier, a type of IC package used for semiconductor integrated circuits.

　　Conventional THz Generation Methods

　　Conventional methods for generating terahertz waves include the ‘frequency multiplication’ method, which converts the frequency of an electrical signal into an integer multiple for output, and the “photomixing” method that produces terahertz waves from the difference frequency created when two laser beams of different wavelengths are mixed in a photomixer. Both approaches necessitate large or medium sized costly equipment to generate terahertz waves.

　　Dynamic Range

　　A performance metric for analog devices indicating the difference or ratio between the maximum and minimum values of a signal that can be handled. Like for other radio frequency applications, for terahertz waves dynamic range usually expressed in decibels (dB).