Giant peak of the Inverse Faraday effect in the band gap of magnetophotonic microcavity

Abstract

Optical impact on the spin system in a magnetically ordered medium provides a unique possibility for local manipulation of magnetization at subpicosecond time scales. One of the mechanisms of the optical manipulation is related to the inverse Faraday effect (IFE). Usually the IFE is observed in crystals and magnetic films on a substrate. Here we demonstrate the IFE induced by fs-laser pulses in the magnetic film inside the magnetophotonic microcavity. Spectral dependence of the IFE on the laser pulse wavelength in the band gap of the magnetophotonic microcavity has a sharp peak leading to a significant enhancement of the IFE. This phenomenon is explained by strong confinement of the electromagnetic energy within the magnetic film. Calculated near field distribution of the IFE effective magnetic field indicates its subwavelength localization within 30 nm along the film thickness. These excited volumes can be shifted along the sample depth via e.g. changing frequency of the laser pulses. The obtained results open a way for ultrafast optical control of magnetization at subwavelength scales.

Layer-selective magnetization switching in the chirped photonic crystal with GdFeCo

“…There are various complicated methods for depth-resolved magnetization probing, for instance, by means of X-rays 41 etc. However, the method proposed here is based on the measurement of the Faraday effect [32][33][34][35][36][37][38][39][40][41][42][43][44] at a single wavelength of laser diode and could be easily implemented in data reading devices.…”

“…We propose to use the photonic crystals, which are all-dielectric structures that allow to reconfigure the electromagnetic field distribution by the frequency detuning 29,30 . The magnetophotonic crystal (MPC) structures [31][32][33][34] , i.e., the multilayer nanostructures containing the magnetic layers were shown to perform tunable localization of light at the resonant frequencies enabling the enhancement of the optomagnetic interaction in a magnetic material 34 .…”

Heisenberg representation of nonthermal ultrafast laser excitation of magnetic precessions

“…It avoids problems caused by material heating, which limits a repetition frequency due to a required cooling time and a recording density due to heat diffusion. Therefore, the demonstration of the UIFE, in which magnetic oscillations in canted antiferromagnet DyFeO 3 were induced by circularly polarized ultrashort laser pulses [5], motivated intensive theoretical [6][7][8][9][10][11][12][13][14][15][16][17][18] and experimental [19][20][21][22][23] studies of this process. A significant progress in development of techniques of ultrafast spin control using femtosecond laser pulses based on the UIFE was demonstrated in recent years [22,[24][25][26][27][28][29][30][31][32][33].…”

Broadband Enhancement of Faraday Effect Using Magnetoplasmonic Metasurfaces

“…where αF is the Faraday rotation per unit path length, χ is the magnetic susceptibility, n is the refractive index, M ⃗⃗⃗ is the magnetization vector, and k ⃗ is the wavevector [1,2]. Faraday effect finds applications in various optical devices including isolators [3][4][5], circulators [6][7][8], and spatial light modulators [9][10][11], as well as data storage [12][13][14], sensing/imaging systems [15][16][17], and in the growing field of spintronics [18,19]. Despite these applications, the small magnitude of the specific Faraday rotation in the majority of MO materials limits its applicability and prevents miniaturization of the MO devices [20].…”