時間分解電子顕微鏡とは？

Key Takeaways

• Electron microscopy (EM) is an imaging technique that uses laser beam technology to view specimens at a micro or nano level
• Scanning electron microscopy (SEM) uses deflector coils to alter laser beam path, while transmission electron microscopy (TEM) uses a fluorescent screen to generate an image
• Meanwhile, time-resolved electron microscopy (TREM) involves the irradiation of samples with short electron pulses to capture snapshots at specific intervals, determined by electron beam pulse length. The technique is used by researchers to correlate spatial data with ultrafast temporal resolution
• The benefits of time-resolved electron microscopy include its high spatial and temporal resolution, with pulses operating at extremely high speeds, close to the femtosecond regime
• TREM is used to provide detailed insights into sample composition, dynamics, and structure

Contents

1. What is electron microscopy?
2. A brief introduction to SEM & TEM
3. What is time-resolved electron microscopy?
4. How does time-resolved electron microscopy work?
5. Discover leading time-resolved electron microscopy solutions

 

What is Electron Microscopy?

Electron microscopy (EM) is a powerful imaging technique renowned for its outstanding spatial resolution. It surpasses the theoretical maximum. Resolving power of conventional microscopy by several orders of magnitude, enabling researchers to probe nanoscale structures and to resolve the chemical composition of samples with unprecedented precision. However, standard EM systems are typically unsuited to monitoring the change of macromolecular structures over time. For that, researchers must employ time-resolved electron microscopy.

SEMとTEMの簡単な紹介

Before delving into the basics of time-resolved electron microscopy, it is worthwhile outlining the basic working principles of EM. Conventional microscopy uses visible light to magnify objects/surfaces up to a theoretical maximum of 1000x. This so-called resolving limit is imposed by the wavelengths of visible light. Electrons have much shorter wavelengths than light which is detectable by the human eye. In fact, an electron beam can be used to magnify objects up to an unprecedented 200,000x with exceptional degrees of chemical specificity. There are two main types of EM: scanning electron microscopy (SEM), and transmission electron microscopy (TEM). These differ in the way that samples are illuminated. However, each one uses the same basic apparatus to generate a focused electron beam which is directed onto the object of interest. They differ in that an SEM uses a series of deflector coils to alter the beam path. Raster scan the sample, while a TEM uses a fluorescent screen to generate a projection image. Each of these systems tends to use a continuous wave (CW) electron beam, which cannot provide relevant temporal data.

時間分解電子顕微鏡とは？

Although many critical dynamics and structures can be investigated using traditional SEM or TEM, it is often important to analyse systems at more stringent timescales. Time-resolved electron microscopy is employed where researchers need to correlate their spatial data with ultrafast temporal resolution. This solution has been developed as a direct result of relatively recent advances in laser technology. Particularly, in the field of ultrafast pulsed wave (PW) laser systems. Femtosecond laser technology – with ultrashort pulses and high repetition rates – is the leading solution for this space.

How Does Time-Resolved Electron Microscopy Work?

The basic principle of operation for time-resolved electron microscopy systems involves the irradiation of a sample with short electron pulses which capture rapid snapshots at specific intervals, determined by the length of these electron beam pulses. Most time-resolved electron microscopy electron beams feature pulses approaching the femtosecond regime, providing detailed insights into sample composition, dynamics, and structure with both high spatial and temporal resolution.

Discover Leading Time-Resolved Electron Microscopy Solutions

We are proud to be a world-leading manufacturer of ultrafast laser sources for demanding areas of application. We offer time-resolved electron microscopy solutions based on our own proprietary ultrafast laser systems. If you would like to learn more about using femtosecond lasers for time-resolved EM, contact us today.