Photonic structures: characterization, modelling, and applications

Introduction
Experimental setups
Research activity
Photonic structures: characterization, modelling, and
applications
Kamil Postava and Jaromı́r Pištora
Nanotechnology Centre, IT4Innovations National Computing Center, and
Department of Physics
Technical University of Ostrava,
17. listopadu 15, 70833 Ostrava-Poruba, Czech Republic
e-mail: [email protected], [email protected]
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
1 / 23
Introduction
Experimental setups
Research activity
Technical University of Ostrava
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
2 / 23
Introduction
Experimental setups
Research activity
Technical University of Ostrava
Nanotechnology Center (head: Jaromı́r Pištora)
7 faculties
more than 17 000 students
about 1500 employee
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
3 / 23
Introduction
Experimental setups
Research activity
IT4 Innovations – supercomputer center in TU Ostrava
www.it4i.cz
hardware
◮
◮
2000 TFlop/s
computing performance
40th most powerfull
supercomputer in the
word
software – ANSYS, COMSOL, FLUENT, MATLAB, etc.
– high performance computing (HPC)
research – Modeling for Nanotechnology – one of 7 workprograms
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
4 / 23
Introduction
Experimental setups
Research activity
Spectroscopic ellipsometry
optical characterization of thin films and nanostructures
◮
spectroscopic ellipsometry UVISEL (Horiba Jobin Yvon, France)
phase modulation technique, spectral range 0.6–6.5 eV
◮
Mueller matrix ellipsometry RC2 (Wollam, USA)
dual rotating compensator,
spectral range 0.7–6.4 eV
spectra of complete Mueller matrix
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
5 / 23
Introduction
Experimental setups
Research activity
Infrared spectroscopy
infrared spectroscopy and microscopy
◮
◮
◮
◮
Fourier transform infrared (FTIR)
spectrometer VERTEX 70v (Bruker)
spectral range 8000–100 cm−1
(1.25–100 µm)
infrared microscope HYPERION 2000
reflection and transmission unit, ATR
unit, VW accessory, liquid and gas cells
phase modulation external ellipsometer
– PEM (HINDS Instruments)
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
6 / 23
Introduction
Experimental setups
Research activity
THz time domain spectroscopy
THz spectral range – TPS Spectra 3000 – TeraView
time resolved spectroscopy – fibre optics pulsed laser
spectral range 0.06 – 3 THz (wavelength 100 µm – 5 mm)
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
7 / 23
Introduction
Experimental setups
Research activity
Equipment for magnetic characterization
magnetic characterization of thin
films and nanostructures
◮
◮
◮
◮
◮
magneto-optic vector magnetometry
at fixed wavelength
magneto-optic microscopy
vibrating sample magnetometry
magnetic force microscopy (MFM)
hystergraph, magnetostriction
measurement
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
8 / 23
Introduction
Experimental setups
Research activity
Research activity
ellipsometry, polarimetry, and spectroscopy (UV–infrared, THz)
ab-initio calculation
magnetoplasmonic gratings, plasmonic of semiconductors
solar cells, photovoltaic
terahertz (THz) sources (lasers) and nonreciprocal isolators
spin-lasers, application of spintronics in light sources
photonic structures in security holograms
magneto-optics (vector magnetometry, quadratic effects, material
sensitivity)
We are searching for collaboration and future projects
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
9 / 23
Introduction
Experimental setups
Research activity
1. Magneto-optical non-reciprocity → optical isolator
protection of a laser
against spurious reflections
optical isolator for fiber
telecommunications
Unique non-reciprocity of magneto-optical effects
−→ unidirectional transmission, nonreciprocal isolators, and
circulators.
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
10 / 23
Introduction
Experimental setups
Research activity
Optical response of magnetoplasmonic grating
grating thickness h = 160nm
100
Cavity mode:
∆ Rp [%], Rp [%]
(C)
50
0
Rp
∆ Rp
−50
0.5
1
Photon energy [eV]
1.5
(A)
(B)
Plasmon modes:
(field confinement in
MO material; YIG)
L. Halagačka, et. al., Coupled mode enhanced giant magnetoplasmonics transverse Kerr
effect, Opt. Express 21, 21741–21755 (2013).
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
11 / 23
Introduction
Experimental setups
Research activity
Experimental optical data of fabricated structures
Optical spectroscopy: Mueller matrix
measurement (193–1700 nm)
Focused beam of the experimental setup –
300 µm
Finite spectral resolution: measured data at the
wavelength λ
reflectivity
optical isolation ratio
1
0.02
0.6
δ Rp/Rs
Rp/Rs
0.8
0.03
model
data
0.4
model
data
0.01
0
−0.01
0.2
0
−0.02
500
1000
wavelength [nm]
K. Postava, J. Pištora
1500
−0.03
Technical University of Ostrava
500
1000
wavelength [nm]
1500
March 2, 2016
12 / 23
Introduction
Experimental setups
Research activity
2. Spin-lasers
What is the spin-laser?
new class of laser devices in which spin polarization of injected carriers
(electrons, holes) is controlled
emitted light polarization is directly related to the electron spin due to the
angular momentum conservation
advantages – lower threshold, control of emitted light polarization, fast
modulations
Frougier J., et al., Appl. Phys. Lett. 103 (2013) 252402
T. Fordos, K. Postava, H. Jaffres, J. Pistora, Matrix approach for modeling of emission from multilayer spin-polarized
light-emitting diodes and lasers, J. Opt. 16 (2014) 065008.
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
13 / 23
Introduction
Experimental setups
Research activity
Modeling and characterization of spin-lasers
Theoretical and experimental investigation of these effects in
multilayer spin-lasers (spin-VCSELs)
joint PhD study of Tibor Fordos
Ecole Polytechnique, Prof. H. Drouhin and Unité Mixte de Physique
CNRS/Thales Dr. H. Jaffres.
T. Fordos; H. Jaffres; K. Postava; J. Pistora; H. J. Drouhin; Properties of linear birefrigence of InGaAs/GaAsP semiconductor
spin-VECSELs: From experiment to theory and models, MORIS 2015, Penang, Malajsie (invited).
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
14 / 23
Introduction
Experimental setups
Research activity
3. THz lasers and isolators
Materials for solid state terahertz lasers and isolators
Ecole PolytechniqueUniversité Lille 1, Prof. J.-F. Lampin and Dr. M.
Vanwolleghem.
joint PhD study of Martin Miçica
M. Micica, V. Bucko, K. Postava, M. Vanwolleghem, J.-F. Lampin, and J. Pistora, Analysis of Wire-Grid Polarisers in Terahertz
Spectral Range, J. Nanosci. Nanotechnol. 16, 1-4, (2016, in press).
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
15 / 23
Introduction
Experimental setups
Research activity
3. Novel structures for Solar cells
Theoretical and experimental investigation of materials and
nanostructures for solar cells applications
collaboration with Laboratoire de Physique des Interfaces et Couches
Minces (LPICM), École Polytechnique, Prof. P. Roca i Cabarrocas.
joint PhD study of Zuzana Mrazková
Z. Mrázková, A. Torres-Rios, R. Ruggeri, M. Foldyna, K. Postava, J. Pištora,
P. Roca i Cabarrocas, Thin Solid Films 571 (2014) 749-755.
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
16 / 23
Introduction
Experimental setups
Research activity
Novel structures for Solar cells
Theoretical and experimental investigation of diffraction from
structured sollar-cells surfaces
T. Kohut, K. Postava, Z. Mrazkova, M. Foldyna, P. Roca i Cabarrocas, M. Micica, and J. Pistora, Modeling of Mueller matrix
response from diffracting structures, J. Nanosc. Nanotechnol. 16, 1-4, (2016, in press).
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
17 / 23
Introduction
Experimental setups
Research activity
Modeling of holographic gratings
– collaboration with Optaglio – Optical Microstructure Technologies
used as security protection against falsification for banknote, ID cards,
taxstam, goods
based on electron beam lithography
3D object visualization using hologram
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
18 / 23
Introduction
Experimental setups
Research activity
5. Modeling of blazed holographic gratings
α
Λ
N=75, φ=18o α=20o
0.8
0.8
0.8
0.8
0.6
0.4
0.6
0.4
0.2
−50
0
0
50
Angle of diffraction (degree)
o
Diffracted intensity
1
Diffracted intensity
1
0
0.6
0.4
0.2
−50
o
0
0
50
Angle of diffraction (degree)
o
N=75, φ=−12 α=20
0.6
0.4
0.2
−50
o
0
0
50
Angle of diffraction (degree)
o
N=75, φ=−22 α=20
o
0.8
0.8
0.8
0.8
0.2
0
0.6
0.4
0.2
−50
0
0
50
Angle of diffraction (degree)
o
Diffracted intensity
1
Diffracted intensity
1
0.4
0.6
0.4
0.2
−50
o
o
N=75, φ=−52 α=20
0
0
50
Angle of diffraction (degree)
0.4
0.2
−50
o
o
N=75, φ=−62 α=20
0
0
50
Angle of diffraction (degree)
o
0.8
0.8
0.2
0
0.2
−50
0
50
Angle of diffraction (degree)
K. Postava, J. Pištora
0
Diffracted intensity
0.8
Diffracted intensity
0.8
Diffracted intensity
1
0.4
0.6
0.4
0.2
−50
0
50
Angle of diffraction (degree)
0
0
50
Angle of diffraction (degree)
o
N=75, φ=−82 α=20
1
0.6
−50
o
N=75, φ=−72 α=20
1
0.4
o
0.6
1
0.6
0
50
Angle of diffraction (degree)
N=75, φ=−42 α=20
1
0.6
−50
o
N=75, φ=−32 α=20
1
Diffracted intensity
Diffracted intensity
N=75, φ=−2o α=20o
1
0.2
Diffracted intensity
N=75, φ=8o α=20o
1
Diffracted intensity
Diffracted intensity
N=75, φ=28o α=20o
0.6
0.4
0.2
−50
0
50
Angle of diffraction (degree)
Technical University of Ostrava
0
−50
0
50
Angle of diffraction (degree)
March 2, 2016
19 / 23
Introduction
Experimental setups
Research activity
6. MO material selectivity from periodic multilayers
1. Co and NiFe layers in the multilayer periodic system
[Ni80 Fe20 (2 nm)/Au(2 nm)/Co(0.4, 0.8, and 1.2 nm)/Au(2 nm)]10
Polar Kerr rotation
50
0
0
−20
Si wafer
−50
−5
0
5
MO contribution of Co
M /M
−5
0
5
MO contribution of NiFe
1
1
0.5
0.5
S
X 10
Co
0
0
−0.5
−0.5
P
Au 2 nm
Co 0.8 nm
Au 2 nm
NiFe 2 nm
Polar Kerr ellipticity
20
mdegree
Au 2 nm
Co 0.8 nm
Au 2 nm
NiFe 2 nm
Au 2 nm
Co 0.8 nm
Au 2 nm
NiFe 2 nm
−1
NiFe
−1
−5
0
5
Magnetic field (kOe)
−5
0
5
Magnetic field (kOe)
K. Postava, I. Sveklo, M. Tekielak, P. Mazalski, A. Maziewski, A. Stupakiewicz, M. Urbaniak, B. Szymański, and F. Stobiecki,
IEEE Trans. Magn. 44, 3261–3264 (2008).
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
20 / 23
Introduction
Experimental setups
Research activity
MO material selectivity from self-assembled nanostructure
2. Self-assembled BiFeO3 –CoFe2 O4 biferroic nanostructures
polar Kerr effect, incidence angle 11◦ , wavelength 650 nm
Polar hysteresis loop
Polar hysteresis loop
0.2
0
−0.2
−0.4
−1
CoFe 2O4
SrTiO 3 (001)
−0.5
0
0.5
Magnetic field (T)
1
1
0
−1
−1
−0.5
0
0.5
Magnetic field (T)
1
0.5
0.5
0
P
M /M
S
S
Second phase
1
P
First phase
1
M /M
BiFeO 3
Kerr ellipticity (mrad)
Kerr rotation (mrad)
0.4
−0.5
0
−0.5
−1
−1
−1
−0.5
0
0.5
Magnetic field (T)
1
−1
−0.5
0
0.5
Magnetic field (T)
1
K. Postava, D. Hrabovský, O. Životský, J. Pištora, N. Dix, R. Muralidharan, J. M. Caicedo, F. Sánchez, and J. Fontcuberta, J.
Appl. Phys. 105, 07C124 (2009).
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
21 / 23
Introduction
Experimental setups
Research activity
MO material selectivity – effect of buffer layer
3. Co grown on self-assembled Au islands
sapphire/Mo(20 nm)/Au(islands)/Co(2 nm)/Au(5 nm)
prepared by MBE, Au islands grows at 500◦ C
First phase
First phase
Au (5 nm)
Co (2 nm)
Au islands
Mo(110) (20 nm)
sapphire substrate
First phase
0.1
0.2
0.1
0.05
0.1
0.05
0
0
0
−0.05
−0.1
−0.05
−0.1
−4
−2
0
2
Magnetic field (kOe)
4
−0.2
−4
−2
0
2
Magnetic field (kOe)
Second phase
4
−0.1
−4
0.01
0.04
0.02
0.005
0.02
0.01
0
0
0
−0.005
−0.02
−0.01
−0.01
−4
−2
0
2
Magnetic field (kOe)
polar
4
−0.04
−4
−2
0
2
Magnetic field (kOe)
longitudinal
−2
0
2
Magnetic field (kOe)
4
Second phase
Second phase
4
−0.02
−4
−2
0
2
Magnetic field (kOe)
4
transverse
K. Postava, D. Hrabovský, J. Pištora, A. Wavro, L.T. Baczewski, I. Sveklo, A. Maziewski,
Thin Solid Films 519, 26272632 (2011).
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
22 / 23
Introduction
Experimental setups
Research activity
MO material selectivity
4. α−Fe crystallites in FeNbB amorphous ribbon
longitudinal Kerr rotation θKs and ellipticity ǫKs
J. Hamrlová, K. Postava, O. Životský, D. Hrabovský, J. Pištora, P. Švec, D. Janičkovič, A. Maziewski, Acta Phys. Pol. A 118,
837 (2010).
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
23 / 23
Introduction
Experimental setups
Research activity
Acknowledgment
PhD students
Lukáš Halagačka, Tibor Fördös, Zuzana Mrazková, Mratin Mičica, Jan Chochol
Collaboration, sample preparation
H. Jaffrés, J.-M. George, H.-J. Drouhin, M. Foldyna, P. Roca i Cabarocas,
Ecole Polytechnique, Unite Mixte de Physique CNRS/Thales, France
M. Cada,
Dalhousie University, Halifax, Canada
B. Dagens, P. Beauvillain,
Institut dElectronique Fondamentale, UMR CNRS 8622, Université Paris-Sud XI, Orsay, France
M. Vanwolleghem, F. Vaurette, J.-F. Lampin
Institut d’Electronique, Microelectronique et Nanotechnologie, CNRS UMR 8520, University of Lille, Villeneuve-dAscq, France
I. Sveklo, A. Stupakiewicz, A. Maziewski,
Laboratory of Magnetism, University of Bialystok, 41 Lipowa Street, 15-424 Bialystok, Poland
K. Postava, J. Pištora
Technical University of Ostrava
March 2, 2016
24 / 23