Terahertz Sources and Diagnostics
The Terahertz band is the last frontier in the electromagnetic spectrum that remains widely unexplored because of the lack of powerful and compact sources. However, the last two decades have seen tremendous progress, resulting in the routine generation of several MV/cm field strengths through compact laser-based schemes. At HI Jena we develop state-of-the-art ultra-high power THz sources and advanced diagnostics. This includes the detailed investigation of THz generation processes using table-top laser systems which in turn allow us to understand the laser—matter interaction process with unprecedented spatio-temporal resolution. Our latest efforts focus on the application of THz pulses in nonlinear optics, solid state physics and particle acceleration.
Our research focuses mainly on
- Developing state-of-the-art high power and high repetition rate THz sources and THz diagnostics.
- Employing THz radiation as an inherent and non-invasive tool to investigate complex plasma processes.
- Development of advanced diagnostics for imaging of extremely low-density systems and dielectric materials in the THz spectral range.
- THz-driven linacs for particle acceleration
- Electro-optical diagnostics to visualize the transient bunch profile
High-power THz sources
Short-pulse laser—plasma interaction has been established as a viable scheme for THz generation. This includes interaction of laser pulses with gases or solid materials. We investigate the influence of laser and plasma parameters on the THz yield and spectrum. Towards this end we employ single-color and bicolor schemes.
Characterization of the THz radiation is equally important in optimizing the THz source as well as for designing potential applications. Spatially and temporally integrated and resolved, as well as polarization dependent, diagnostics are used for this purpose.
EO diagnostics for extracting the longitudinal bunch profile of the charged particle beams
We employ two independent non-invasive diagnostics based on the electro-optical (EO) effect and Smith-Purcell radiation (SPR) to estimate the transient features of the particle bunches.
With this project we aim to improve the acceleration efficiency by alternative schemes, such as post-acceleration of ions and protons using self-generated terahertz radiation. THz radiation with suitable pulse duration and high field strengths can be a good candidate for accelerating charged particles. The wavelength is long enough to utilize miniature accelerating structures with conventional machining techniques and the short pulse duration allows for a limited amount of pulsed heating.