THz devices

The spectral range of the TeraHertz (THz) ranges from about 100 GHz to some THz. In this spectral range of many elements such as wood, concrete, or paper are transparent which gives this type of radiation a certain interest for many applications. The realization of emission and detection devices operating in this wavelength range represents one of the great challenges of modern electronics and optoelectronics. Indeed, the conventional electronic and optoelectronic components do not make it easy to reach this range of wavelengths.

The approach currently attracting the greatest interest for the THz range is certainly the realization of lasers and quantum cascade detectors. However, their performance and operating temperature are severely limited which remains a major handicap to their large-scale use. This approach is nevertheless very promising because this limitation is related to the intrinsic properties of the materials used so far: GaAs and InP. Wide bandgap (GaN or ZnO) materials have very high LO phonon energies to allow for room temperature operation.

The two GaN and ZnO material channels have been operating at CRHEA since 2015 with a view to producing THz devices via the ANR OPTOTERAGAN and European Fet-Open ZOTERAC projects. Recently structures detecting in the 1-8 THz range have been demonstrated.