Cathodoluminescence

Ultrafast spectroscopy (or Pump-probe spectroscopy) is a technique used to study the dynamics of excited states in various materials, such as molecules, semiconductors, and solids.

It involves the use of two laser pulses. The first laser pulse, the "pump," excites the sample, elevating electrons from the ground state to an excited state. This initiation creates a non-equilibrium condition in the sample. After a controlled delay, a second laser pulse, the "probe," is sent through the sample. The probe pulse interrogates the sample to gather information about the transient states and the evolution of the excited states over time.

By varying the delay time between the pump and probe pulses, researchers can create a time-resolved picture of the dynamic processes occurring in the material. This time resolution can be on the order of femtoseconds (10^-15 seconds), allowing scientists to observe ultrafast phenomena.

These techniques provide insights into ultrafast processes, such as electronic transitions, high-order harmonics generation, molecular vibrations, and energy transfer mechanisms, that occur on very short time scales. It helps in understanding the fundamental properties of materials, such as the relaxation times of excited states, carrier dynamics in semiconductors, topological effects and the mechanisms of photochemical reactions.

Other possible studies can cover the world of solar cells, light-emitting devices, and photocatalysts, where understanding the dynamics of excited states is essential for improving efficiency and performance. Moreover, in biophysics and biochemistry, pump-probe spectroscopy can be used to investigate the dynamics of biomolecules, such as the folding and unfolding of proteins, photosynthesis mechanisms, and the behavior of molecular motors.

Focused ion beam (FIB) systems operate similarly to a scanning electron microscope (SEM), except that instead of a beam of accelerated electrons it takes advantages of accelerated ions. The FIB technique opens to direct writing by sputtering (milling), ion beam implantation and creation of defects to locally modify material properties, ion beam induced deposition of materials exploiting the presence of gas injection systems (GIS) and ion beam lithography. The secondary SEM column could be used not only for imaging,  but for electron beam lithography on resist and electron beam induced material depositions exploiting the GIS tool. FIB systems can be equipped with different detectors: Everhart-Thornley SE, In-lens SE detector, Backscattered Detector, EDX. In the micro-nanofabrication area, FIB is used to create 2D and 3D features at the nanometer scale. FIB can pattern a diverse range of materials into features like dots, lines, and arrays with high precision. Both FIB milling and electron beam lithography can achieve similar resolution for 2D patterns. When coupled with a GIS, FIB can create 3D features with exceptional resolution, down to a few nanometers. This allows for the fabrication of intricate 3D structures with remarkable detail and precision.