High-resolution confocal microscopy with simultaneous electron and laser beam irradiation.

Area of Science:

• Materials Science
• Optical Microscopy
• Electron Microscopy

Background:

• Combining optical and electron microscopy offers complementary analytical capabilities.
• Existing methods often lack integrated excitation sources for multimodal analysis.
• High spatial resolution is crucial for correlating optical and electronic properties.

Purpose of the Study:

• To develop a fiber-based confocal optical microscope integrated within a scanning electron microscope (SEM).
• To enable simultaneous or sequential excitation of samples using both laser and electron beams.
• To achieve high spatial resolution for correlated optical and electron beam analyses.

Main Methods:

• Integration of single-mode optical fibers into a commercial SEM via vacuum feedthroughs.
• Utilizing optical fibers as pinholes for confocal microscopy with a NA=0.3 objective.
• Performing simultaneous photoluminescence (PL) and cathodoluminescence (CL) measurements.

Main Results:

• Achieved a spatial resolution of approximately 2 μm.
• Demonstrated excellent light collection efficiency.
• Successfully tested the system by analyzing europium ions in GaN thin films.

Conclusions:

• The developed instrument effectively combines photoluminescence and cathodoluminescence microscopy within an SEM.
• The high spatial resolution ensures optimal overlap between laser and electron beam excitation.
• This integrated system provides a powerful tool for in-situ characterization of materials.