ABSTRACT
The THz frequency range coincides with many low-energy modes in all phases of matter, i.e., plasma, gases, liquids, and solids that render it an excellent candidate for basic research. Furthermore, THz radiation can serve not only as a probe but also to control excitations like magnons and phonons. In terms of applications, THz imaging and sensing have recently gained considerable scientific attention. Applications in biomedicine, security, military, quality control and inspection such as in pharmaceutical and circuitry manufacturing, have been enabled in recent years due to the development of versatile THz sources based on photonic technologies. Despite this progress in THz technology, there is still a need for stronger, more efficient and broad bandwidth THz sources. To this end, the field of ultrafast spintronics with a focus on THz spintronics is a novel direction that has high potential to be an innovative part in the 144development of new THz sources and even to overcome existing THz technologies with respect to bandwidth. This chapter focuses on experimental approaches of ultrafast spintronics to generate broadband THz electromagnetic pulses. First, we will introduce the field of THz spintronics and then we will analyse the physics of the spin-to-charge-current conversion leading to the subsequent THz emission. We will present experimental configurations to generate and detect spintronic THz pulses and finally we will give an overview of strategies to engineer intensity and bandwidth of the emitted THz signal.
