Optimised Spintronic Emitters of Terahertz Radiation for Time-Domain Spectroscopy

Wagner FM, Melnikas S, Cramer J, Damry DA, Xia CQ, Peng K, Jakob G, Klaeui M, Kicas S, Johnston MB (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Journal of Infrared, Millimeter, and Terahertz Waves Springer Verlag (Germany)

Book Volume: 44

Pages Range: 52-65

Journal Issue: 1-2

DOI: 10.1007/s10762-022-00897-9

Abstract

Spintronic metal thin films excited by femtosecond laser pulses have recently emerged as excellent broadband sources of terahertz (THz) radiation. Unfortunately, these emitters transmit a significant proportion of the incident excitation laser, which causes two issues: first, the transmitted light can interfere with measurements and so must be attenuated; second, the transmitted light is effectively wasted as it does not drive further THz generation. Here, we address both issues with the inclusion of a high-reflectivity (HR) coating made from alternating layers of SiO2 and Ta2O5. Emitters with the HR coating transmit less than 0.1% of the incident excitation pulse. Additionally, we find that the HR coating increases the peak THz signal by roughly 35%, whereas alternative attenuating elements, such as cellulose nitrate films, reduce the THz signal. To further improve the emission, we study the inclusion of an anti-reflective coating to the HR-coated emitters and find the peak THz signal is enhanced by a further 4%.

Involved external institutions

University of Oxford GB United Kingdom (GB) State research institute Center for Physical Sciences and Technology LT Lithuania (LT) Johannes Gutenberg-Universität Mainz (JGU) DE Germany (DE)

How to cite

APA:

Wagner, F.M., Melnikas, S., Cramer, J., Damry, D.A., Xia, C.Q., Peng, K.,... Johnston, M.B. (2023). Optimised Spintronic Emitters of Terahertz Radiation for Time-Domain Spectroscopy. Journal of Infrared, Millimeter, and Terahertz Waves, 44(1-2), 52-65. https://doi.org/10.1007/s10762-022-00897-9

MLA:

Wagner, Ford M., et al. "Optimised Spintronic Emitters of Terahertz Radiation for Time-Domain Spectroscopy." Journal of Infrared, Millimeter, and Terahertz Waves 44.1-2 (2023): 52-65.

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