학술논문
Coated Spintronic Emitters for Improved THz Time-domain Spectroscopy
Document Type
Conference
Author
Source
2023 48th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2023 48th International Conference on. :1-2 Sep, 2023
Subject
Language
ISSN
2162-2035
Abstract
Spintronic metal thin films excited by femtosecond laser pulses have proven to be excellent sources of broadband THz radiation, making these emitters increasingly popular for THz spectroscopy. Unfortunately, a significant proportion of the incident excitation laser is transmitted through the spintronic emitters, which can inadvertently photoexcite samples or cause damage to elements of the spectrometer. Here, we demonstrate a high-reflectivity coating made from alternating layers of SiO 2 and Ta$_{{2}} {\mathrm{O}} _{{5}}$ that effectively blocks the incident excitation pulse and enhances the peak THz electric field by roughly 35%. We further improve the emitter performance with an anti-reflective coating. We find spintronic emitters with both coatings exhibit over 40% improvement in peak THz electric field compared to an uncoated emitter and transmit less than 0.1% of the excitation laser pulse.