Photoelectron tomography with an intra-cavity velocity-map imaging spectrometer at 100 MHz repetition rate

Abstract

We present a compact velocity-map imaging (VMI) spectrometer for photoelectron imaging at 100 MHz repetition rate. Ultrashort pulses from a near-infrared frequency comb laser are amplified in a polarization-insensitive passive femtosecond enhancement cavity. In the focus, multi-photon ionization (MPI) of gas-phase atoms is studied tomographically by rotating the laser polarization. We demonstrate the functioning of the VMI spectrometer by reconstructing photoelectron angular momentum distributions from xenon MPI. Our intra-cavity VMI setup collects electron energy spectra at high rates, with the advantage of transferring the coherence of the cavity-stabilized femtosecond pulses to the electrons. In addition, the setup will allow studies of strong-field effects in nanometric tips.

Fast and precise chiroptical spectroscopy by photoelectron elliptical dichroism

“…Velocity map imaging spectroscopy in an optical cavity was recently demonstrated, 35,36 using a sophisticated optical scheme relying on frequency combs. In this setup, the laser pulses coherently add up in the resonant cavity, producing an enhancement of the laser intensity enabling multiphoton ionization studies to be conducted at very high repetition rates (100 MHz).…”

IoT Agricultural Pest Identification Based on Multiple Convolutional Models

“…The inverse color transformation of an image is to make black pixels white and white pixels black. The generalized inverse color [28] transformation can also be applied to color images, i.e., complementing all pixel points, and the inverse image processing can enhance white or gray details in dark areas. The effect of the inverse color transformation of an image is shown in Figure 12.…”