Optimization of magneto-optical response of FeF2∕Fe∕FeF2 sandwiches for microwave field detection

Abstract

Articles you may be interested inVisualization of vortex motion in FeAs-based BaFe1.9Ni0.1As2 single crystal by means of magneto-optical imagingWe report on optimizing the magneto-optical ͑MO͒ response of dielectric/Fe/dielectric sandwich structures for microwave B-field sensor applications. We have performed experimental MO spectroscopic and simulation studies of FeF 2 / Fe/ FeF 2 sandwiches with varying both top and bottom FeF 2 layer thicknesses. We evaluate the performance of the sensor with MO figure of merit ͑off-diagonal reflection coefficient͒ rather than with MO polarization state ͑MO azimuth rotation and ellipticity͒. Our simulations indicate that an increase in the modulus of the MO signal by a factor of 17 is feasible compared to the bulk Fe. However, the corresponding enhancement of the figure of merit, which is the relevant parameter, is only threefold. These simulations were carried out for the operating wavelength of sensors at 810 nm. We show, contrary to the general belief, that in order to enhance the MO performance of the sensor it is more important to optimize the bottom dielectric layer rather than the top layer.

Cavity enhancement of the magneto-optic Kerr effect in glass/Al/SnO2/PtMnSb/SnO2 structure

“…The wavelength of 405 nm is the emission wavelength of GaN-based blue-violet laser diodes which are indispensable part of new-generation optical high density data storage systems [18]. As the material for non-magnetic layers, the use of metallic and/or dielectric materials has been common [4,7]. Here, we examine the use of a transparent semiconductor for enhancing the Kerr signals of PtMnSb.…”

“…This is the case for nearly all metallic magnetic materials. Nevertheless, the blue wavelength MO Kerr effect in such absorbing materials and consequently their performance as high density MO recording media, can be improved by their incorporation into suitable multilayer stacks [4][5][6][7][8][9][10].…”

Analytical analysis of a multilayer structure with ultrathin Fe film for magneto-optical sensing

“…The mw currents generate fringing magnetic fields which cause the magnetization in an adjacent Bi-YIGaG film to precess. The cost, total probe thickness and requirements for B appl can be reduced by using ultrathin ferromagnetic iron layer with the saturation magnetization, µ 0 M s = 2.158 Tesla [5], instead of Bi-YIGaG films (about 3 µm thick) on 500 µm GGG substrates where µ 0 M s is more than two orders in magnitude smaller [1,6]. The magnetization component perpendicular to the film surface can be detected with linear (in magnetization) magneto-optical (MO) effects leading to linearity between the currents and MO response.…”

“…One system designed for the operating wavelength of 810 nm (Ti:sapphire laser) employed the layer sequence Au/FeF 2 /Fe/FeF 2 /Ag/GaAs [6,13]. One system designed for the operating wavelength of 810 nm (Ti:sapphire laser) employed the layer sequence Au/FeF 2 /Fe/FeF 2 /Ag/GaAs [6,13].…”

“…Note that FeF 2 required the protection with an Au capping. The sandwiching of the ultrathin iron with dielectrics transformed the smooth MO polar Kerr effect spectrum with broad lines of bulk Fe [6,13,14] to a MO spectrum with sharp peaks in both MO polar Kerr rotation and ellipticity located close to a desired laser wavelength. Prior the deposition, the MO response was evaluated using a transfer matrix model [15,16].…”