| Autor: |
Hosseini, Seyedeh Maryam, Javaheri, Amin Sadraei, Jahangiri, Fazel, Hamidi, Seyedeh Mehri, Latif, Hamid |
| Předmět: |
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| Zdroj: |
Journal of Theoretical & Applied Physics; Jan/Feb2024, Vol. 18 Issue 1, p1-11, 11p |
| Abstrakt: |
We study the improvement of terahertz collection efficiency in a THz-TDS system based on a spintronic THz emitter, by exploring the effect of substrate impedance matching. This improvement is obtained by properly coupling a hyper-hemispherical lens fabricated from suitable THz materials to a non-magnetic (NM)|ferromagnetic (FM)|substrate emitter structure. The emitter is a Ni|Pt bilayer film coated on a MgO substrate. The refractive index and the dispersion properties of the substrate are adjusted according to the impedance matching conditions and consequently for the maximum THz collection efficiency by a photoconductive antenna (PCA). By comparing various substrates, including MgO, Al2O3, SiO2, and polyethylene terephthalate (PET), our results reveal that the power of the THz radiation collected from the Ni|Pt|MgO with the hyper-hemispherical Si-lens coupler is 64.5 times larger than that from the Ni|Pt|MgO without the lens coupler. A PET substrate in direct contact with a hyper-hemispherical Teflon-lens could be a favorable choice for improved collection efficiency of STE-induced THz radiation, in the absence of Silens. These results could be considered useful to achieve the guidelines for scaling the THz radiation power emitted from the spintronic THz emitter according to the employed substrate and hyper-hemispherical lens. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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