Applications
Time-Resolved Photoemission Spectroscopy
Angle-resolved photoemission spectroscopy (ARPES) is used to analyze the electronic band structure in momentum and energy space for superconductors, topological insulators, transition metal dichalcogenides, and other crystalline materials. In ARPES, a deep-UV laser beam is sent onto the surface. The electrons are emitted by the photoelectric effect above the vacuum level and then collected by a detector, scanned around the sample. Analyzing the energy and momentum of the emitted electron provides the required information for a complete electronic bandstructure mapping.
Time- and angle-resolved photoemission spectroscopy (TR-ARPES) extends and complements conventional ARPES by adding femtosecond temporal resolution. TR-ARPES resolves elementary scattering processes directly in the electronic band structure as a function of energy and electron momentum due to the simultaneous measurement of the spectral and dynamic information. In such a pump-probe scheme, a femtosecond infrared laser pulse excites the sample by electron-hole pair creation, and a delayed UV pulse probes momentum and energy of electrons in the conduction band.
The ideal laser source for TR-ARPES produces deep UV photons at a high repetition rate (hundreds of kHz or higher). Intermediate pulse energy is also advantageous because high pulse energies can cause parasitic space charge effects at the measured surface. Typically, the UV photon is generated by high harmonic generation (HHG) in solids or gases.
Optical parametric amplifiers (OPAs), such as ORPHEUS-MIR and ORPHEUS-N, and optical parametric chirped-pulse amplifiers (OPCPAs) provide state-of-the-art solutions for TR-ARPES.
- Few cycle pulses in a compact footprint
- 800 nm, 1600 nm, 2000 nm, or 3000 nm output
- High repetition rate, up to MHz
- Industrial-grade pump, up to 320 W, 8 mJ
- Exceptional power and pulse energy stability
- CEP stabilization option
- Broad-bandwidth MIR pulses at high repetition rate
- Continuously tunable in 2500 – 15 000 nm range
- Short-pulse high-energy auxiliary output at 2000 nm
- Pumped by industrial-grade lasers for high stability
- CEP-stable option
- NOPA for the shortest tunable pulses
- Pulse duration down to < 30 fs
- Integrated prism compressor
- Adjustable spectral bandwidth and pulse duration
- Wavelength feedback with internal spectrometer
- Continuous tunability from UV to MIR, 190 – 16000 nm
- High energy and high power models for all needs
- Single-shot – 2 MHz repetition rate
- Up to 80 W pump power
- Up to 2 mJ pump pulse energy
- Tunable pulse duration, 100 fs – 20 ps
- Maximum pulse energy of up to 4 mJ
- Down to < 100 fs right at the output
- Pulse-on-demand and BiBurst for pulse control
- Up to 5th harmonic or tunable extensions
- CEP stabilization or repetition rate locking
- Thermally-stabilized and sealed design
- Tunable pulse duration, 190 fs – 20 ps
- Maximum output of 80 W and 2 mJ
- Single-shot – 2 MHz repetition rate
- Pulse-on-demand and BiBurst for pulse control
- Up to 5th harmonic or tunable extensions
- Air-cooled model
- Compact industrial-grade design
- 515 nm, 343 nm, 258 nm, and 206 nm outputs
- Simple selection of active harmonic
- Simultaneous or switchable outputs
- Models for PHAROS / CARBIDE and FLINT
Spatiotemporal imaging of charge transfer in photocatalyst particles
R. Chen, Z. Ren, Y. Liang, G. Zhang, T. Dittrich, R. Liu, Y. Liu, Y. Zhao, S. Pang, H. An et al., Nature 7931 (610), 296-301 (2022).
Investigation of the non-equilibrium state of strongly correlated materials by complementary ultrafast spectroscopy techniques
H. Hedayat, C. J. Sayers, A. Ceraso, J. van Wezel, S. R. Clark, C. Dallera, G. Cerullo, E. D. Como, and E. Carpene, New Journal of Physics 3 (23), 033025 (2021).
Spatially heterogeneous ultrafast interfacial carrier dynamics of 2D-MoS2 flakes
Y. Liang, B. Li, Z. Li, G. Zhang, J. Sun, C. Zhou, Y. Tao, Y. Ye, Z. Ren, and X. Yang, 21, 100506 (2021).
Ultrafast generation and decay of a surface metal
L. Gierster, S. Vempati, and J. Stähler, Nature Communications 1 (12) (2021).
A combined laser-based angle-resolved photoemission spectroscopy and two-photon photoemission spectroscopy study of Td–WTe2
P. Hein, S. Jauernik, H. Erk, L. Yang, Y. Qi, Y. Sun, C. Felser, and M. Bauer, Journal of Physics: Condensed Matter 34 (32), 345503 (2020).
Coherent narrowband light source for ultrafast photoelectron spectroscopy in the 17–31 eV photon energy range
R. Cucini, T. Pincelli, G. Panaccione, D. Kopic, F. Frassetto, P. Miotti, G. M. Pierantozzi, S. Peli, A. Fondacaro, A. D. Luisa et al., Structural Dynamics 1 (7), 014303 (2020).
Extreme ultraviolet time- and angle-resolved photoemission setup with 21.5 meV resolution using high-order harmonic generation from a turn-key Yb:KGW amplifier
Y. Liu, J. E. Beetar, M. M. Hosen, G. Dhakal, C. Sims, F. Kabir, M. B. Etienne, K. Dimitri, S. Regmi, Y. Liu et al., Review of Scientific Instruments 1 (91), 013102 (2020).
High resolution time- and angle-resolved photoemission spectroscopy with 11 eV laser pulses
C. Lee, T. Rohwer, E. J. Sie, A. Zong, E. Baldini, J. Straquadine, P. Walmsley, D. Gardner, Y. S. Lee, I. R. Fisher et al., Review of Scientific Instruments 4 (91), 043102 (2020).
Spontaneous Exciton Dissociation at Organic Semiconductor Interfaces Facilitated by the Orientation of the Delocalized Electron–Hole Wavefunction
T. R. Kafle, B. Kattel, S. Wanigasekara, T. Wang, and W. Chan, Advanced Energy Materials 10 (10), 1904013 (2020).
Femtosecond time-resolved spectroscopic photoemission electron microscopy for probing ultrafast carrier dynamics in heterojunctions
B. Li, G. Zhang, Y. Liang, Q. Hao, J. Sun, C. Zhou, Y. Tao, X. Yang, and Z. Ren, 4 (32), 399-405 (2019).