Time-Domain Spectroscopy Group: Labs & Techniques
Time-Domain Spectroscopy Techniques
The potential of time-domain spectroscopy techniques for space applications in e.g. robotic missions is investigated. The research is motivated by the recent emergence of compact, space ready femtosecond lasers. The underlying idea is that short pulse laser-based spectroscopy techniques have shown in terrestrial applications that they can cover a very wide frequency range, from the ultra-violet to the deep THz, based on opto-electronic (nonlinear) photonics technologies in the near-infrared spectral range. Thereby complex, opto-mechanic spectrometer concepts and sophisticated direct detector designs can be avoided. Time-domain techniques have furthermore the potential to be compatible with chip-integration. Our aim is to develop breadboard models for different use cases, e.g. to investigate the geochemistry of planetary materials, and benchmark their performance with respect to conventional, frequency-domain techniques such as Raman or FTIR spectroscopy. Currently two techniques are in the focus of the research, which shall initially enable to operate in a frequency range between 0.1 and 30 THz.
(i) Coherent Phonon Spectroscopy (CPS), which enables to identify (planetary) materials by their coherent phonon fingerprint via detecting the modulation of the complex dielectric function in the time-domain.
(ii) Terahertz time-domain spectroscopy, which enables the determination of the complex dielectric function of (planetary) materials via sampling the electric field of transmitted, reflected or emitted coherent Terahertz light pulses in the time-domain.
Example: coherent phonon spectroscopy schemes (top) and a CPS benchmark experiment on Quartz (bottom) ©DLR
Short-pulse Laser Spectroscopy Laboratory
The short-pulse laser spectroscopy laboratory is a climatized laboratory, equipped with state-of the art short-pulse laser systems to enable research and development in the area of time-domain-spectroscopy techniques. The following laser systems and pulse parameters are available:
1.Revolution Nd:YLF laser
- wavelength: 527 nm
- pulse duration: 150 ns
- pulse energy: 30 mJ
- repetition rate: 1 kHz
2.Vitara Laser-oscillator system delivering laser pulses with the following parameters:
- wavelength: 800nm
- pulse duration: 40fs
- pulse energy: 3nJ
- repetition rate: 78 MHz
3.Astrella Laser-amplifier system delivering laser pulses with the following parameters:
- wavelength: 800nm
- pulse duration: 85fs
- pulse energy: 7mJ
- repetition rate: 1kHz
4.Opera Solo optical parametric amplifier system delivering laser pulses with the following parameters:
- wavelength: 1 – 20 µm
- pulse duration: ~ 100 fs
- pulse energy: 500 µJ @ 1µm to 5µJ @ 20µm
- repetitions rate: 1kHz
The lab is furthermore equipped with different auxiliary equipment to characterize the pulse properties such as pulse energy meters, interferometers or autocorrelators.
Femtosecond laser systems in the short-pulse laser laboratory and pulse diagnostics (left) and available pulse energies (right). ©DLR
Fourier-Transform Infrared Spectroscopy
Broadband Infrared (IR) and Terahertz (THz) Spectroscopy is performed in a frequency range between 1 and 740 THz. The measurements are performed with a commercial Bruker 80V spectrometer which is furthermore equipped with modules for Raman and Photoluminescence measurements under infrared excitation at 1064 nm. IR/THz Transmission and reflection measurements as well as Raman and Luminescence measurements are routinely performed on solid samples. Samples can be investigated under cryogenic conditions down to 5 K. The typically investigated materials range from samples relevant to space research (e.g. meteorites, samples from sample return missions, planetary surface simulants, frozen volatiles) to samples of interest for solid state technology (e.g. silicon- & diamond-based optoelectronics, photonics, quantum technology). Another capability is the characterization of the infrared optical properties of components considered for mission instrumentation.
FTIR spectrometer in the broadband Terahertz spectroscopy laboratory. The instrument is also equipped with a Raman and Photoluminescence module. ©DLR
References:
S. G. Pavlov , D. D. Prikhodko , S. A. Tarelkin , V. S. Bormashov , N. V. Abrosimov , M. S. Kuznetsov, S.A. Terentiev, A. Nosukhin , Yu. Troschiev , V. D. Blank, H.-W. Hübers, “Resonant boron acceptor states in semiconducting diamond”, Phys. Rev. B 104, 155201 (2021).
S.G. Pavlov, L.M. Portsel, V.B. Shuman, A.N. Lodygin, Y.A. Astrov, N.V. Abrosimov, S.A. Lynch, V.V. Tsyplenkov, H-W Hübers, “Infrared absorption cross sections, and oscillator strengths of interstitial and substitutional double donors in silicon”, Phys. Rev. Mat. 5, 114607 (2021).
S.G. Pavlov, Y.A. Astrov, L.М. Portsel, V.B. Shuman, А.N. Lodygin, N.V. Abrosimov, H.-W. Hübers, "Magnesium-related shallow donor centers in silicon.", Materials Science in Semiconductor Processing 130, 105833 (2021).
D.D. Prikhodko, S.G. Pavlov, S.A. Tarelkin, V.S. Bormashov, M.S. Kuznetsov, S.A. Terentiev, S.A. Nosukhin, S.Y. Troschiev, H.-W. Hübers, V.D. Blank, "Large substitutional impurity isotope shift in infrared spectra of boron-doped diamond.", Phys. Rev. B 102, 155204 (2020).
(Nonlinear) Terahertz Spectroscopy on Quantum Materials
Quantum materials such as topological insulators, graphene or semiconductors with shallow donors are investigated in order to elucidate their potential as building block in novel nonlinear photonic devices such as THz emitters or THz mixers. For that purpose, high-field THz pulses with a field strength of beyond 100 kV/cm are generated by optical rectification in nonlinear crystals and optimized THz time-domain detection schemes are developed to quantitatively determine efficiencies for frequency multiplication and frequency mixing processes. Measurements of this type are also frequently performed at the High-field THz facility TELBE (HZDR, Dresden) and FLASH (DESY, Hamburg) or the infrared free electron laser facilities FELIX (Radbourg University Nijmegen) and FELBE (HZDR, Dresden).
© Juniks, Dresden, CC-BY
Examples Terahertz spectroscopy on quantum materials: Terahertz high harmonic generation in biased graphene (left) and nonlinear Terahertz spectroscopy on topological insulators (right) © Juniks, Dresden, CC-BY
References:
S. G. Pavlov, N. Deßmann, V. N. Shastin, R. Kh. Zhukavin, B. Redlich, A. F. G. van der Meer, M. Mittendorff, S. Winnerl, N. V. Abrosimov, H. Riemann, H.-W. Hübers, „Terahertz Stimulated Emission from Silicon Doped by Hydrogenlike Acceptors“, Phys. Rev. X 4, 021009 (2014).
H.A. Hafez, S. Kovalev, K.-J. Tielrooij, M. Bonn, M. Gensch, D. Turchinovich, "Terahertz Nonlinear Optics of Graphene: From Saturable Absorption to High-Harmonics Generation.", Adv. Opt. Mat. 8, 1900771 (2020).
N. Dessmann, N. H. Le, V. Eless, S. Chick, K. Saeedi, A. Perez-Delgado , S. G. Pavlov, A. F. G. van der Meer, K. L. Litvinenko, I. Galbraith, N. V. Abrosimov, H. Riemann, C. R. Pidgeon, G. Aeppli, B. Redlich, B. N. Murdin, “Highly efficient THz four-wave mixing in doped silicon”, Light Science and Appl. 10, 1 (2021).
S. Kovalev, H. A. Hafez, K.-J. Tielrooij, J.-Ch. Deinert, I. Ilyakov, N. Awari, D. Alcaraz, K. Soundarapandian, D. Saleta, S. Germanskiy, M. Chen, M. Bawatna, B. Green, F. H. L. Koppens, M. Mittendorff, M. Bonn, M. Gensch, D. Turchinovich, "Electrical tunability of terahertz nonlinearity in graphene.", Science Advances 7, eabf9809 (2021).
J.-Ch. Deinert, D. A. Iranzo, P. Pe ́ rez, X. Jia, H. A. Hafez, I. Ilyakov, ́N. Awari, M. Chen, M. Bawatna, A. N. Ponomaryov, S. Germanskiy, M. Bonn, F. H.L. Koppens, D. Turchinovich, M. Gensch, S. Kovalev, K.-J. Tielrooij, "Grating-Graphene Metamaterial as a Platform for Terahertz Nonlinear Photonics.", ACS Nano 15, 1145 (2021).
S. Kovalev, K-J. Tielrooij, J-C. Deinert, I. Ilyakov, N. Awari, M. Chen, A. Ponomaryov, M. Bawatna, T. VAG de Oliveira, L.M. Eng, K.A. Kuznetsov, D.A. Safronenkov, G. Kh. Kitaeva, P.I. Kuznetsov, H.A. Hafez, D. Turchinovich, M. Gensch, “Terahertz signatures of ultrafast Dirac fermion relaxation at the surface of topological insulators“, npj Quantum Materials 6, 84 (2021).
Z. Chen, C.B. Curry, R. Zhang, F. Treffert, N. Stojanovic, S. Toleikis, ... & S.H. Glenzer, "Ultrafast multi-cycle terahertz measurements of the electrical conductivity in strongly excited solids.", Nat. Comm. 12, 1 (2021).
Photonic Instrumentation Development
The expertise within the Time-Domain spectroscopy group in laser spectroscopy, optic design, detector development, scientific programming, photon diagnostics and qualification of spectroscopy components is employed in different cross-sectoral projects in the Institute of Optical Sensor Systems. Recent examples are contributions to the MMX-RAX Projekt (validation of the optics design, qualification of the laser and other optical components), to the LIBS system for the ARCHES Rover (control software) and the OSAS B project (software and detector technology). The group furthermore developed a Photonic Integrated Circuit Inspector and a Photoemission-microscope set-up in collaboration with, respectively for, commercial partners. The developed system targets fundamental research activities on integrated circuits (ICs). It combines different imaging and analyzing techniques in one compact multi-purpose tool to study security mechanisms of ICs against manipulation and spying as well as their aging and failure mechanisms.
Example photonic instrumentation development: Photonic Integrated Circuit Inspector: principal layout (left) and picture of an instrument before delivery to a commercial partner (right). ©DLR
The group is also actively involved at different 4th generation light source projects such as FLASH and TELBE, contributing to instrumentation development for e.g. advanced photon diagnostics. One example is the recent demonstration of a new concept to characterize pulse properties such as arrivaltime, duration or pulse energy of ultra.-short light pulses in the extreme-ultra violet. The XUV light pulses are transformed into Terahertz waveforms which contain
Example photonic instrumentation development: Terahertz-wave decoding of femtosecond XUV light pulses as demonstrated at the FERMI XUV FEL (a). The application as arrivaltime monitor is shown (b,c). Adapted with permission from I. Ilyakov et al, "Terahertz-wave decoding of femtosecond extreme-ultraviolet light pulses", Optica 9, 545-550 (2022) © The Optical Society.
References:
S. Frohmann, E. Dietz, H. Dittrich, H.-W. Hübers, "Picosecond imaging of signal propagation in integrated circuits.", Av. Opt. Techn. 6, 137 (2017).
T. Tanikawa, S Karabekyan, S. Kovalev, S. Casalbuoni, V. Asgekar, S. Bonetti, S. Wall, T. Laarmann, D. Turchinovich, P. Zalden, T. Kampfrath, A.S. Fisher, N. Stojanovic, M. Gensch, G.A. Geloni, "Volt-per-Ångstrom terahertz fields from X-ray free-electron lasers.", Journ. Synch. Rad. 27, 796 (2020).
M. Chen, J.-C. Deinert, B. Green, Z. Wang, I. Ilyakov, N. Awari, M. Bawatna S. Germanskyi, T. V. A. G. De Oliveira, G. Geloni, T. Tanikawa, M. Gensch, S. Kovalev, "Pulse- and field-resolved THz-diagnostics at 4th generation lightsources.", Opt. Exp. 27, 375675 (2019).
T. Oelze, O. Kulyk, B. Schütte, U. Frühling, E. Klimešová, B. Jagielski, L. Dittrich, M. Drescher, R. Pan, N. Stojanovic, V. Polovinkin, K. P. Khakurel, K. Muehlig, I. J. Bermudez Macias, S. Düsterer, B. Faatz, J. Andreasson, M. Wieland, and M. Krikunova, "THz streak camera performance for single-shot characterization of XUV pulses with complex temporal structures.", Opt. Exp. 28, 20686 (2020).
I. Ilyakov, N. Agarwal, J.-C. Deinert, J. Liu, A. Yaroslavtsev, L. Foglia, G. Kurdi, R. Mincigrucci, E. Principi, G. Jakob, M. Kläui, T. S. Seifert, T. Kampfrath, S. Kovalev, R. E. Carley, A. O. Scherz, and M. Gensch, "Terahertz-wave decoding of femtosecond extreme-ultraviolet light pulses", Optica 9, 545-550 (2022).