Terahertz Magneto-Optic Sensor/Imager

Abstract

We are reporting a new type of compact magneto-optic sensor constructed from terahertz-wave spintronic emitter and electro-optic detector. the corresponding terahertz polarization output of the emitter and the detection phase-sensitivity of the detector depend on the vector of the external magnetic field. The emitter/detector pair consists of two small and thin wafers sandwiched together and capped with a thin gold mirror. As a result, the use of bulky terahertz steering/collection optics was completely eliminated in our magneto-optic imager. With such simple on-chip generation/detection scheme for terahertz time-domain setup in reflection-type geometry, we were able to record the rasterscanned image contrast of a permanent magnet in the proximity of the sensor surface. the contrast strongly varies with the magnet orientation and its position with respect to the sensor. the imager spatial resolution depends on chip optical quality for tight femtosecond-laser pump/probe crossfocusing at detector/mirror interface and terahertz generation/detection efficiency. In this respect, the chip robustness to the pump/probe fluences is also an important factor to consider.

Advances in Magnetic‐Field Assisted Photoelectrochemical Systems for Highly Efficient Conversion of Renewable Energy

“…Reproduced under the terms of the CC‐BY 4.0 license. [ 147 ] Copyright 2020, The Authors, published by Springer Nature. c) Spectrogram near the frequency of the optical beat note.…”

“…[ 144–146 ] Magneto‐optic imaging (MOI), based on emitters of spintronic THz and detectors of electro‐optic (EO) THz for time‐domain spectroscopy (TDS), has been used to observe the dependence of spin electrons on a magnetic field. [ 147 ] Schematic of reflection‐type THz‐TDS MOI device with EO sampling is shown in Figure 10b. Light beam crashes the magneto‐optic sensors chip from the side of spintronic layer and leads to the generation of electron currents in the vertical direction.…”

Terahertz chiral sensing and magneto-optical enhancement for ferromagnetic nanofluids in the chiral metasurface

“…For further development of the THz application system, there is a high demand for efficient devices for sensing and manipulating THz waves in their amplitude, phase, and polarization [5][6][7][8] . The unique magnetic anisotropy, nonreciprocity, and magnetic tunability of magneto-optical material make them play an irreplaceable role in the isolator, magneto-optical polarization convertor, modulator, and magnetic field sensor [9][10][11][12][13][14] . However, researches on the magnetic properties of THz waves lag seriously, so it is necessary to fill the "terahertz gap" by not only electrical but also magnetic means.…”

Entangled spintronic modulated high‐performance Ce 2 O 3 small polaron surface state‐based water splitting cells

“…The magnetooptic sensor which prepared from Fe/Pt spintronic emitter demonstrated the high spatial resolution as 0.2 μm, but the poor magnetic field sensitivity induces the low image contrast. 26 The worse thing is the magnetic tunnel induced the spintronic logic with larger change resistance than the other memories devices, which induce the low reading and loading speed. Some scientists released some research works as some attempts about enhancing the performance of the spin Hall Effect.…”

“…Transition metal added Heusler alloys CoXMnAs ( X = Ru, Rh) demonstrated a promising ability in spintronic excitation, thermoelectric and thermodynamic properties for energy conversion system, 20 and from Ab initio study, the electronic, magnetic, optical, and thermoelectric characteristics of K 2 OsX 6 ( X = Cl, Br) are well defined, 25 which give the orbital spin coupling a bright side to achieve spintronic injection system. The magneto‐optic sensor which prepared from Fe/Pt spintronic emitter demonstrated the high spatial resolution as 0.2 μm, but the poor magnetic field sensitivity induces the low image contrast 26 . The worse thing is the magnetic tunnel induced the spintronic logic with larger change resistance than the other memories devices, which induce the low reading and loading speed.…”