Studying Quantum Coherence on Metal Surfaces with IMPULSE+iNOPA

High electron density materials elicit an ultrafast coherent response when interacting with light, from sub-femtosecond to a few femtoseconds, which makes experimental observation highly difficult.
To meet this challenge, the research group of Professor Hrvoje Petek at the University of Pittsburgh used an IMPULSE laser pumped iNOPA from Clark-MXR, Inc. to measure the quantum coherence of Ag(111) by means of a multidimensional spectroscopy method called Interferometric Time-Resolved Multiphoton Photoemission (ITR-mPP).
The coherent nonlinear polarizations investigated in ITR-mPP are directly related to high-harmonic generation (HHG) from metal surfaces. HHG at high frequencies is another application enabled by use of the IMPULSE laser.
Link: Coherent Two-Dimensional Multiphoton Photoelectron Spectroscopy of Metal Surfaces (https://doi.org/10.1103/PhysRevX.9.011044)