Methodology and implementation of a tunable deep-ultraviolet laser source for photoemission electron microscopy

Area of Science:

• Surface Science
• Materials Science
• Spectroscopy

Background:

• Photoemission electron microscopy (PEEM) requires intense UV to soft X-ray light sources for high-resolution imaging.
• Traditionally, PEEM instruments relied on synchrotron facilities for suitable light sources.
• Advancements in laser technology enable laboratory-based PEEM systems.

Purpose of the Study:

• To characterize a novel laser-based deep-UV light source for PEEM.
• To evaluate its performance and impact on image quality.
• To demonstrate its utility for laboratory-based surface analysis.

Main Methods:

• Integration of a tunable wavelength, high repetition rate laser with a harmonics generation module.
• Generation of deep-UV radiation spanning 192 nm to 210 nm.
• Characterization of spectral properties, laser stability, and space charge effects in PEEM.

Main Results:

• The laser system provides stable deep-UV light (192-210 nm).
• High UV laser fluxes were analyzed for space charge effects.
• Imaging of gallium nitride demonstrated significantly improved image quality compared to conventional sources.

Conclusions:

• Laser-based deep-UV light sources are viable for advanced laboratory PEEM.
• This technology offers an alternative to synchrotrons for surface electronic property studies.
• Improved image quality facilitates detailed analysis of materials and surfaces.