The optical spectroscopies setups,

equipped with:

1. Wide spectral range spectroscopic ellipsometer

based on rotating analyzer technique equipped with SPEX-500 monochromator and MgF2 polarizers, working in the photon energy range 0.8-5.5 eV (225-1550 nm light wavelength range).

2. Wide-range magneto-optical spectral magnetometer

working in the same spectral range in the polar, longitudinal, and transversal magneto-optical Kerr, and also Faraday configurations. The magnetometer is equipped with electromagnets producing magnetic field in the range up to +/-2T depending on configuration, CaF2 Hinds photoelastic modulator, and both setups with photomultipliers and solid state detectors. The Kerr magnetometers together with spectral ellipsometer allows to determine complete dielectric tensor elements in the 0.8-5.5 spectral range. All setups and measuring procedures are computerized.
The magnetometer is distinguished by high accuracy and sensitivity up to 3 x 10-5 deg of Kerr rotation angle. This allowed to measure, among others, very weak Kerr rotation and ellipticity in nonmagnetic Cu, Ag, and Au noble metals (L. Uba, S. Uba, V.N. Antonov, Phys. Rev. B 96, 235132 (2017)).

The second harmonics and ultrafast magnetization dynamics setups,

equipped with:

1. Femtosecond oscillator

Spectra-Physics Tsunami, with parameters up to 30 fs of 80 MHz repetition pulses up to 5 nJ pulse energy.
The ocscillator allowed to measure second harmonics (SHG) and magnetization-induced (MSHG) effects in transparent dielectrics with high sensitivity (A. Bonda, S. Uba, L. Uba, Phys. Rev. B 87, 024426 (2013), Appl. Phys. Lett. 105,191608 (2014), J. Appl. Phys. 117, 213104 (2015))

2. Femtosecond regenerative amplifier

Spectra-Physics Spitfire Ace laser system (=800 nm, up to 35 fs pulses of 10 kHz repetition up to 5 mJ pulse energy) with Optical Parametric Amplifier – Topas Prime for 295-2600 nm spectral range. The amplifier is equipped with electromagnets able to produce magnetic field in the range +-/9 kOe oriented at angles in the range 0-55 deg with respect to sample normal or up to 20 deg from sample plane for fields up to +/-5 kOe. All setups and measuring procedures are computerized.

The setup allows to measure transient Kerr rotation, ellipticity, and reflection coefficient by time resolved pump-probe technique at 800 and 400 nm of laser pulse wavelengths, up to 10 mJ/cm2 pump pulse fluence within 0-4 ns time window.

The setup allowed to discovery large slowing down effect of magnetization dynamics in Ni-Mn-Sn Heusler alloy thin film close to the Curie temperature (A. Bonda, L. Uba, K. Załęski, and S. Uba, Phys. Rev. B 99, 184424 (2019)).

Contact: dr Adam Bonda (a.bonda@uwb.edu.pl), dr hab. Luba Uba (ubaluba@uwb.edu.pl),
dr hab. Stanisław Uba (uba@uwb.edu.pl)