Search results for "Terahertz time-domain spectroscopy"
showing 6 items of 6 documents
A wideband THz Time Domain Spectroscopy table-top system based on ultrafast pulsed laser: Model and experiments
2014
We present an analytical model carefully describing the time-frequency behavior of all the stages composing our whole Terahertz Time Domain Spectroscopy laser based system, from the THz pulses generation via Optical Rectification, to their detection through Electro-Optic Sampling technique, by way of diffraction, collecting and focusing effects. In order to prove the effectiveness of our work, we report on the comparison among the experimental waveforms and the simulation results.
Broadband Terahertz Probes of Anisotropic Magnetoresistance Disentangle Extrinsic and Intrinsic Contributions
2021
Anisotropic magnetoresistance (AMR) is a ubiquitous and versatile probe of magnetic order in contemporary spintronics research. Its origins are usually ascribed to extrinsic effects (i.e. spin-dependent electron scattering), whereas intrinsic (i.e. scattering-independent) contributions are neglected. Here, we measure AMR of polycrystalline thin films of the standard ferromagnets Co, Ni, Ni81Fe19 and Ni50Fe50 over the frequency range from DC to 28 THz. The large bandwidth covers the regimes of both diffusive and ballistic intraband electron transport and, thus, allows us to separate extrinsic and intrinsic AMR components. Analysis of the THz response based on Boltzmann transport theory revea…
Spin-resolved terahertz spectroscopy
2016
As such, terahertz spectroscopy cannot resolve the spin structure of conducting particles. Here we introduce the spin sensitivity to terahertz spectroscopy by using the spin-valve configuration of the sample. As a result, the number density and momentum scattering time of conduction electrons in a ferromagnetic metal can be resolved according to their spin.
Ultra-broadband terahertz time domain spectroscopy by Solid State Biased Coherent Detection
2017
The spectral fingerprint of ibuprofen within the THz frequency window has been retrieved through an ultra-broadband THz Time Domain Spectrometry set-up. The latter implements the Solid State Biased Coherent Detection scheme, based on a compact CMOS-compatible integrated device. Such a technique shows unprecedented advantages in term of bandwidth (greater than 10 THz) over other solid state methods like electro-optic sampling.
Efficient metallic spintronic emitters of ultrabroadband terahertz radiation
2016
Terahertz electromagnetic radiation is extremely useful for numerous applications such as imaging and spectroscopy. Therefore, it is highly desirable to have an efficient table-top emitter covering the 1-to-30-THz window whilst being driven by a low-cost, low-power femtosecond laser oscillator. So far, all solid-state emitters solely exploit physics related to the electron charge and deliver emission spectra with substantial gaps. Here, we take advantage of the electron spin to realize a conceptually new terahertz source which relies on tailored fundamental spintronic and photonic phenomena in magnetic metal multilayers: ultrafast photo-induced spin currents, the inverse spin-Hall effect an…
Terahertz time-domain spectroscopy based on photoconductive antennas
2016
In this work, we present our first experimental results obtained by means of a THz-TDS setup based on photoconductive antennas (PCAs). The main elements of the setup are: i) a mode-locked Ti:Sapphire femtosecond laser (Mai-Tai SP - Spectra Physics), providing optical pulses at 800±20 nm with a duration < 50 fs and repetition rate of 84 MHz; ii) two photoconductive antennas, made in LT-GaAs (Low-Grown Temperature Gallium Arsenide), operating as THz emitter and detector; iii) an optical delay line.