Related papers: Current-enhanced broadband THz emission from spint…
Identifying materials with an efficient spin-to-charge conversion is crucial for future spintronic applications. The spin Hall effect is a central mechanism as it allows for the interconversion of spin and charge currents. Spintronic…
Emerging communications and computing technologies will rely ever-more on expanding the useful radio frequency (RF) spectrum into the sub-THz and THz frequency range. Both classical and quantum applications would benefit from advancing…
Coupling phase-stable single-cycle terahertz (THz) pulses to scanning tunneling microscope (STM) junctions enables spatio-temporal imaging with femtosecond temporal and \r{A}ngstrom spatial resolution. The time resolution achieved in such…
The idea to utilize not only the charge but also the spin of electrons in the operation of electronic devices has led to the development of spintronics, causing a revolution in how information is stored and processed. A novel advancement…
Polarization control of THz light is of paramount interest for the numerous applications offered in this frequency range. Recent developments in THz spintronic emitters allow for a very efficient broadband emission, and especially unique is…
The concepts in this thesis comprise three groups focusing on: (1) fast electron sources, (2) THz injectors, and (3) THz linacs. First, the feasibility of ultrafast, high-yield electron emitters based on nanostructured cathodes is…
Recent intense electrical and optical studies of graphene have pushed the material to the forefront of optoelectronic research. Of particular interest is the few terahertz (THz) frequency regime where efficient light sources and highly…
Coherent, continuous-wave, and electrically tunable chip-scale terahertz (THz) sources are critical for emerging applications in sensing, imaging, spectroscopy, communication, space and quantum technologies. Here, we demonstrate a robust…
We show that to correctly describe the ultrafast currents in spintronic THz emitters it is necessary to take charge equilibration into account. The charge current which is locally induced by a fs laser pulse and the inverse spin-Hall effect…
Terahertz (THz) technology enables multi-Tbps satellite communications, but conventional semiconductor detectors suffer from fundamental performance degradation above 1 THz due to the Drude limit of free electrons. Here, we theoretically…
Broadband electro-optic intensity modulators are essential to convert electrical signals to the optical domain. The growing interest in THz wireless applications demands modulators with frequency responses to the sub-THz range, high power…
Terahertz (THz) wave shows great potential in non-destructive testing, bio detection and cancer imaging. Recent progresses on THz wave near-field probes/apertures enable mechanically raster scanning of an object's surface in the near-field…
Platinum (Pt) is the element with the largest spin Hall conductivity and is known as the most efficient spin-to-charge conversion material in spintronic THz emitters. By alloying with aluminum (Al), its resistivity can be substantially…
Recently, there has been a growing interest in integrated THz photonics for various applications in communications, spectroscopy and sensing. We present a new integrated photonic platform based on active and passive elements integrated in a…
We describe the electronic control of extraordinary terahertz transmission through subwavelength metal hole arrays fabricated on doped semiconductor substrates. The hybrid metal-semiconductor forms a Schottky diode structure, where the…
Ultrafast THz radiation generation from ferromagnetic/nonmagnetic bilayer heterostructure-based spintronic emitters generally exploits the conversion from spin- to charge-current within the nonmagnetic layer and its interface with the…
A superconducting microstrip half-wavelength resonator is proposed as a suitable band-pass filter for broadband moderate spectral resolution spectroscopy for terahertz (THz) astronomy. The proposed filter geometry has a free spectral range…
This paper investigates the propagation and radiation of spin waves in gyroelectric waveguides within the terahertz (THz) frequency range. With applications in imaging, spectroscopy, and integrated circuits, THz radiation has garnered…
Controlling the directionality of emitted far-field thermal radiation is a fundamental challenge in contemporary photonics and materials research. While photonic strategies have enabled angular selectivity of thermal emission over narrow…
Uniaxial spintronic heterostructures constitute compact THz emitters under femtosecond optical excitation, with emission amplitude and polarization governed by the applied magnetic field is presented. We demonstrate here efficient…