Nonlinear magneto-optics is a very sensitive fingerprint of the electronic, magnetic, and atomic structure of surfaces, interfaces, and thin ferromagnetic films. Analyzing theoretically the nonlinear magneto-optical Kerr effect for thin films of Fe(001) and at Fe surfaces we demonstrate exemplarily how various electronic material properties of ferromagnets , such as the d-band width, the magnet...

We report a combined experimental-computational investigation of the electronic structure of CrO2. We have measured the magneto-optical Kerr spectra of CrO2 at 10 K and 300 K. At 10 K the Kerr signal is significantly enhanced over that obtained at 300 K. We compare the measured Kerr spectra to first-principles theoretical spectra, which we computed using three different approximations to the ex...

A nonlinear metasurface is demonstrated numerically based on the recently developed quantum-sized gold film. The active functionality of the metasurface is realized by varying the incident optical power through the ultrahigh Kerr nonlinearity of the quantum-sized gold films. In the low power region, the device acts as a normal reflecting surface, while it becomes a phase grating with most energ...

The sensitivity of the magneto-optical Kerr response to electronic thermalization processes in ultrafast pump–probe experiments is studied by evaluating the complex conductivity tensor of Ni for non-equilibrium electron distributions. The electronic structure and optical matrix elements are calculated within density functional theory. To account for the electronic redistributions generated by t...

An optical probe current sensor module using the Kerr effect of exchange-coupled magnetic film has been fabricated and applied to switching current measurements for IGBT used for the DC-DC converter and the DC-AC inverter of EV/HEV. Since the sensor module using the Kerr effect of the single domain exchange-coupled magnetic film utilizes magnetization rotation only, Barkhausen noise due to doma...

An innovative liquid crystal display (LCD), incorporating in-plane switching mechanism with LC nanoencapsulation, is developed and its electro-optic (EO) performances are characterized. The nanoencapsulated LCDs exhibit electric-field induced transitions from an optically-isotropic state to an anisotropic one based on Kerr effect. Extremely small size of LC droplets embedded in the nanoencapsul...

Co2FeSi(100) films with L21 structure deposited onto MgO(100) were studied exploiting both longitudinal (LMOKE) and quadratic (QMOKE) magneto-optical Kerr effect. The films exhibit a huge QMOKE signal with a maximum contribution of up to 30mdeg, which is the largest QMOKE signal in reflection that has been measured thus far. This large value is a fingerprint of an exceptionally large spin-orbit...

Optical whispering gallery mode (WGM) resonators have been very attracting platforms for versatile Kerr frequency comb generations. We report a systematic study on the material dispersion of various optical materials that are capable of supporting quality factors above 109. Using an analytical approximation of WGM resonant frequencies in disk resonators, we investigate the effect of ...

A formalism is developed for the Kerr constant of particles composed of subunits whose electro-optical properties have axial symmetry. A protocol is devised for the calculation of the Kerr constant from the dipole moments and the electrical and optical polarizabilities of the subunits. The conformational average is required if the particle is flexible. Based on that formalism, the Kerr constant...