Time- and Angle- 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 kilohertz 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 time- and angle-resolved photoemission spectroscopy.
Compact, Few-cycle, CEP-stable OPCPA Systems
Broad-Bandwidth Mid-Infrared Optical Parametric Amplifier
Non-Collinear Optical Parametric Amplifier
Collinear Optical Parametric Amplifier
Modular-Design Femtosecond Lasers for Industry and Science
Unibody-Design Femtosecond Lasers for Industry and Science
Free-Standing Harmonic Generator