A new era in terahertz radiation control
Bouchta Sahraoui is a professor at the University of Angers and a member of the Angers Photonics Laboratory (Lphia). He studies the properties of materials to design high-performance photonic and electro-optic devices that meet today's technological challenges. Interview with Bouchta Sahraoui.
Could you please provide an overview of the Image project (2018-2024)?
The primary objective was to develop crystalline and composite materials for optoelectronic and photonic devices in the visible spectrum. The project resulted in the design of materials with optimised anisotropy, characterised by properties that vary according to their orientation. These innovations have led to significantly improved performance for electro-optical, acousto-optical and non-linear optical devices, making these materials competitive on the market. The results are therefore very positive, not only because of the large number of publications produced in collaboration with our partners but also thanks to the arrival of several colleagues from Ukraine, Poland and Germany. This cooperation has strengthened our collaborations and contributed to the international reputation of our university.
Could you please elaborate on the link with the new TeraHertz project (2023-2028), which you are coordinating at the University of Angers, and which is funded under the Marie Sklodowska-Curie Actions (MSCA) with a budget of €184,000?
The Image project has generated many innovative ideas and solutions, which will be transposed and applied to terahertz (THz) and sub-terahertz frequencies as part of the TeraHertz project. The latter focuses on developing new technologies and characterising materials to create advanced devices for controlling terahertz radiation. The collaboration between the two projects will enhance fundamental research and pave the way for revolutionary applications, notably in ultra-high-speed wireless communications, sensors and medical diagnostics.
How are you conducting your research at Lphia with regard to the TeraHertz project?
Our work starts with an in-depth study and precise diagnosis of the nonlinear optical properties of various materials to study in detail their potential application in devices for controlling THz radiation. Among these, lithium niobate (LiNbO₃), both pure and doped, and semiconductors belonging to the II-VI family, such as cadmium telluride (CdTe), zinc sulphide (ZnS) and zinc selenide (ZnSe), are the subject of specific research.
The results will undergo a systematic comparison with those of zinc telluride (ZnTe), a recognised reference material used to generate and detect terahertz pulses. In addition, a new phase will focus on generating THz waves from organic crystals, once the key factors for optimising the conversion efficiency have been identified and controlled.
Subsequently, new materials developed in collaboration with our partners will be studied to extend the range of accessible properties. Part of the funding will be directed towardsthe acquisition of essential equipment, including chemicals, crystals, optical elements and an ultra-fast oscilloscope.
