Higher Power Output and Simple Setup: New Source of Terahertz Radiation
Sensoren, Geräte und Komponenten
- No complex components
- High power output
- Compatible with standard commercial pulsed lasers
- Thin film material widely available
- Nondestructive material testing
- Imaging Security
The search for efficient sources in the THz frequency range is actively pursued in both science and technology due to the significant benefits of THz radiation in applications such as spectroscopy, object imaging or fast data transfer. However, state-of-the-art THz sources require specialized equipment and conditions such as expensive high-quality single crystals (often toxic), lithography for micro- or nano-structuring, application of external fields or cryogenics. In addition, the output power of the most used THz sources is limited and difficult to enhance.
A novel concept for a high-power THz radiation source has been developed to overcome the aforementioned shortcomings. It is based on the transverse thermoelectric effect and can be realized in an uncomplicated arrangement with standard components.
As shown in figure 1, the source assembly comprises a thin film and a pulsed laser. The latter is emitting femtosecond pulses in the optical range thus allowing for the use of standard commercial components. When irradiating the thin film, a laser pulse causes an ultra-fast temperature gradient in the material. The thin film material needs to have an anisotropic Seebeck coefficient in order to show the transverse thermoelectric effect. Various, widely available materials are fulfilling this requirement.
According to the transverse thermoelectric effect in such a thin film material, the temperature gradient triggers an electric field Ex and an electric current jx perpendicular to the temperature gradient. This rapid charge displacement emits radiation in the THz range and a respective arrangement can thus be used as a radiation source.
Being based on the pulsed laser and the thin film only, the invention allows for an uncomplicated yet powerful THz radiation source that can be used in various applications in industry, medicine and beyond.
Yordanov et al., “Intense terahertz radiation via the transverse thermoelectric effect”, arXiv preprint arXiv:2208.01480(2022)
EP (EP4086699A1), PCT
- Ref.-Nr.: 1201-6201-BC (552,3 KiB)
Dr. Bernd Ctortecka, M. Phil.
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