Femtosecond-Level Temporal Resolution of High-Voltage Power Supplies for Electron Microscopes: Technological Breakthroughs and Application Expansion

In the technical system of electron microscopes (hereafter referred to as electron microscopes), the high-voltage power supply is a core unit that controls the acceleration, focusing, and stability of electron beams. Its performance directly determines the electron microscope's observation accuracy and dynamic capture capability of the microscopic world. The temporal resolution of traditional high-voltage power supplies for electron microscopes mostly remains at the nanosecond or even microsecond level, which is insufficient to meet the observation needs of dynamic microscopic processes at the femtosecond scale, such as atomic migration, chemical bond breaking and formation, and conformational flipping of biological macromolecules. The emergence of high-voltage power supplies with femtosecond-level temporal resolution, by increasing the voltage regulation response speed to the order of 10⁻¹⁵ seconds, has opened up a new dimension of dynamic microscopic observation for electron microscopes, promoting the leap from static characterization to real-time tracking in fields such as materials science, life sciences, and catalytic chemistry.
The core value of femtosecond-level temporal resolution in high-voltage power supplies for electron microscopes lies in its precise control capability over the instantaneous energy and trajectory of electron beams. During electron microscope observation, the energy of the electron beam is determined by the accelerating voltage provided by the high-voltage power supply. However, dynamic microscopic processes (such as phase transitions of nanocrystals and dynamic evolution of active sites on catalyst surfaces) are often accompanied by instantaneous changes in energy demand. If the power supply response lags, the electron beam energy cannot match the process requirements in a timely manner, leading to blurriness or distortion of the observation signal. By adopting a new type of topological circuit structure and high-precision closed-loop feedback algorithm, femtosecond-level power supplies can complete micro-adjustments of the accelerating voltage (with a precision of microvolts) within femtoseconds, ensuring that the electron beam is always in a precise tracking state. This enables clear capture of microscopic dynamic details at the femtosecond scale.
In specific application scenarios, high-voltage power supplies with femtosecond-level temporal resolution demonstrate irreplaceable advantages. In the field of materials science, researchers use them to observe the melting-recrystallization dynamic process of metal nanoparticles. When nanoparticles are excited by laser pulses, their structural changes last only a few tens of femtoseconds. Traditional power supplies cannot adjust the electron beam energy in a timely manner, resulting in the loss of key links in the observation results. In contrast, femtosecond-level power supplies can synchronously respond to laser pulse signals and adjust the accelerating voltage in real time, allowing the electron microscope to successfully record the complete process of nanoparticles from lattice disorder to reordering. This provides direct experimental basis for the design of high-performance nanomaterials. In the field of life sciences, this type of power supply helps solve the mystery of conformational dynamics of biological macromolecules. The folding process of proteins involves the rapid spatial rearrangement of amino acid chains, and some key steps last only a few hundred femtoseconds. The femtosecond-level high-voltage power supply stabilizes the electron beam energy, enabling cryo-electron microscopes to capture the intermediate state structures of protein folding, providing a new perspective for understanding the abnormal folding mechanism of disease-related proteins.
Furthermore, in the in-situ observation of catalytic chemistry, high-voltage power supplies with femtosecond-level temporal resolution also play a key role. The reactive active sites on the catalyst surface often have the characteristic of dynamic generation-disappearance, and their lifetime may be only at the femtosecond level. Traditional power supplies are unable to maintain the stable focusing of the electron beam, making the observation of active sites extremely difficult. In contrast, femtosecond-level power supplies can be linked with in-situ reaction devices, adjusting the voltage in real time according to the instantaneous signals (such as photons and ions) generated during the reaction process. This ensures that the electron microscope continuously focuses on the active sites and clearly records their dynamic evolution rules, providing core data support for the development of high-efficiency catalysts.
In the future, as electron microscope technology moves towards the integration of higher spatial resolution + faster temporal resolution, high-voltage power supplies with femtosecond-level temporal resolution will further break through performance boundaries. On the one hand, by integrating more advanced sensing technology, it will realize zero-delay synchronization between voltage regulation and microscopic dynamic processes. On the other hand, by optimizing energy efficiency, it will adapt to the observation needs of in-situ electron microscopes in extreme environments (such as high temperature, high pressure, and strong magnetic fields), continuing to provide stronger technical support for microscopic dynamic scientific research.