Coherent optical spectroscopy characterization of the magnetic properties of oriented Fe3O4 nanoparticles

Abstract

Magnetite (Fe3O4) nanoparticles are widely used in microwave components, such as microwave absorbers and anti-reflection coatings. Their magnetic properties are important for these applications. In this work, the weak magnetic field created by the Fe3O4 nanoparticles was estimated using a coherent-spectroscopy all-optical method for measurement of weak magnetic fields. Both the magnitude and the direction of the magnetic field were evaluated through the position and amplitude of a magneto-optical resonance obtained in a paraffin-coated sensor cell containing Rb vapors. A pump-probe scheme was used to prepare a high-contrast magneto-optical resonance. Different possible geometries related to this concept are discussed, including sensor miniaturization.

Remote detection of the conductivity of current-carrying metallized traces

“…The inset in figure 1 presents a photograph of the sample used in this test experiment after connecting the wires at the ends (the scaling bar is 1 mm). We use the experimental setup described in [7], which is shown schematically in figure 1. The linearly polarized laser beam, 4 mm in diameter (d beam ), of a single mode 794.76 nm DFB diode laser is in resonance with the D 1 line of Rb and passes through the optical cell (with a length of 2.5 mm and a diameter of 2 mm) filled with 87 Rb and coated with paraffin to increase the time of interaction of the alkali atoms with the laser beam.…”