Probing microwave fields and enabling in-situ experiments in a transmission electron microscope

Area of Science:

• Physics
• Materials Science
• Electrical Engineering

Background:

• Characterizing microwave device performance is crucial for developing advanced electronic systems.
• Traditional methods for analyzing electromagnetic fields can be limited in spatial and temporal resolution.
• Understanding dynamic field distributions is essential for optimizing device efficiency and functionality.

Purpose of the Study:

• To introduce a novel technique for evaluating microwave device performance.
• To demonstrate the capability of mapping local electromagnetic field distributions.
• To showcase the application of Lorentz transmission electron microscopy (L-TEM) in analyzing gigahertz frequency fields.

Main Methods:

• Utilizing Lorentz transmission electron microscopy (L-TEM) to probe electromagnetic fields.
• Performing specimen-free experiments to measure field distributions.
• Analyzing the Lorentz forces exerted by propagating electromagnetic fields on an electron beam.
• Varying the gigahertz operating frequency to observe field changes.

Main Results:

• Successfully mapped the polarisation state of electromagnetic fields from a microstrip waveguide.
• Demonstrated the ability to visualize both forward and backward propagating fields.
• Showcased the detection of microwave field effects on specimens, including ferromagnetic resonance.

Conclusions:

• Lorentz transmission electron microscopy (L-TEM) provides a powerful new method for evaluating microwave device performance.
• This technique enables detailed mapping of dynamic electromagnetic fields.
• The method has potential applications in analyzing material-microwave interactions and device behavior.