Background
Terahertz waves refer to electromagnetic waves with a frequency range of around 1 THz (terahertz). Terahertz waves are said to have properties in between those of light and radio waves, and are expected to be applied to non-destructive testing and component analysis of compounds and biological materials. On the other hand, it has been pointed out that the current terahertz wave light sources are not strong enough and are difficult to handle because they require superconductivity and high-frequency lasers. These issues have hindered the widespread use of terahertz waves.
Summary of the technology
Makoto Nakajima, an associate professor at the Institute of Laser Science, Osaka University, has developed a new terahertz light source that can overcome these problems. The new light source is based on the principle of generating terahertz waves by applying laser light to a thin film consisting of ferromagnetic and non-magnetic materials such as iron and cobalt. Dr. Nakajima and his colleagues have further developed this principle and established a technology to use a lens-shaped glass substrate or a plastic film that can be deformed as a substrate for the laminated thin ferromagnetic/non-magnetic film, instead of a flat substrate such as glass. Currently, the researchers are conducting experiments using a terahertz light source made of Fe/Pt. The intensity of this light source is about 40% of that of ZnTe (1 mm) in terms of electric field amplitude. The researchers expect to be able to increase the intensity further, and if realized, the output intensity will be greater than that of the ZnTe light source.
Possible application
A terahertz wave light source created on a lens-shaped substrate generates terahertz waves that are “focused” like ordinary visible light. This makes it possible to omit the use of terahertz wave lenses, which are used in terahertz analysis equipment, but have a problem of high chromatic aberration, leading to cost reduction and higher performance of the equipment. In the case of using a deformable substrate such as plastic, it is possible to create light sources with various shapes such as circular or domed. This will make it easier to develop terahertz devices for everyday use, such as baggage inspection and IC tag reading.
Expectations to companies
Osaka University is looking for companies interested in developing a terahertz light source using this technology and terahertz wave devices using the light source. In developing the technology, Osaka University can provide technical information and conduct experiments in collaboration with the companies. In addition, companies can obtain a license for this technology from Osaka University.
Product No. DA-03580b