Researchers at CU Boulder have developed a novel imaging method employing doughnut-shaped light beams, enhancing the capabilities of ptychography. This advancement enables high-resolution imaging of small, patterned structures such as semiconductors, surpassing the constraints of conventional microscopy. This breakthrough holds significant potential for advancements in nanoelectronics and biological imaging. (Conceptual illustration.) Credit: SciTechPost.com
In a recent study, CU Boulder scientists have utilized doughnut-shaped light beams to capture detailed images of minuscule objects, which traditional microscopes cannot resolve.
Progress in Imaging Nanoelectronics
This new technique could assist researchers in enhancing various nanoelectronic devices, including tiny semiconductors found in computer chips. This innovation was featured on December 1 in a special edition of Optics & Photonics News titled Optics in 2023.
Ptychography: Exploring the Microscopic Realm
This research represents a significant advancement in ptychography, a complex yet effective method for observing extremely small entities. Unlike conventional microscopes, ptychography doesn’t directly observe tiny objects. It involves projecting laser light onto a target and measuring the scattering of light, similar to creating shadow puppets.
Scattering patterns generated by doughnut-shaped light beams reflecting off an object with a repetitive structure. Credit: Wang, et al., 2023, Optica
Addressing the Ptychography Challenge
According to Margaret Murnane, study lead and Distinguished Professor of Physics, ptychography has historically struggled with highly periodic samples, which include many nanoelectronic devices.
She explains that various crucial technologies, such as certain semiconductors composed of atoms arranged in regular patterns, have been challenging to examine closely using ptychography.
Doughnut-shaped light beams scattering from an exceptionally small structure. Credit: Wang, et al., 2023, Optica
Innovation with Doughnut-Shaped Light
However, Murnane and her team have devised a novel method. They replaced traditional lasers with beams of extreme ultraviolet light shaped like doughnuts.
This technique can capture precise images of structures as small as 10 to 100 nanometers, significantly smaller than a millionth of an inch. Moreover, these beams are gentle on tiny electronics, unlike some current imaging tools like electron microscopes.
Murnane notes that this method could be used for inspecting and printing semiconductors without damaging them.
Bin Wang and Nathan Brooks, who received their doctorates from JILA in 2023, were the primary authors of this study.
Expanding Microscope Capabilities
Murnane states that this research pushes the boundaries of microscopes. Traditional lens-based imaging tools are limited to a resolution of about 200 nanometers, insufficient for observing many viruses. Ptychography, developed in the mid-2000s, could surpass this limitation.
Ptychography Mechanics
Consider the shadow puppet analogy. To create a ptychographic image of a tiny structure, scientists scan it with a laser beam multiple times, recording the scattering patterns with sensitive detectors. These patterns are then analyzed with mathematical equations to reconstruct the image.
However, this method struggles with repetitive structures like silicon or carbon grids due to the uniformity of the scatter patterns.
To test their new approach, the researchers produced a carbon atom mesh with a defect, viewed with a doughnut-shaped beam and traditional lasers. Credit: Wang, et al., 2023, Optica
Doughnut Microscopy
In their study, Murnane’s team used extreme ultraviolet light beams shaped into vortices or corkscrews, which create doughnut-shaped patterns when projected onto a flat surface.
These doughnut beams, when interacting with repetitive structures, produce more complex patterns than regular lasers, allowing the team to precisely identify defects in the structures.
Advancing to Finer Detail
The team aims to refine this doughnut beam technique to observe smaller and more delicate objects, including living biological cells.
Reference: “High-fidelity ptychographic imaging of highly periodic structures enabled by vortex high harmonic beams” by Michael Tanksalvala, Henry C. Kapteyn, Bin Wang, Peter Johnsen, Yuka Esashi, Iona Binnie, Margaret M. Murnane, Nicholas W. Jenkins, and Nathan J. Brooks, 19 September 2023, Optica.
DOI: doi:10.1364/OPTICA.498619
Other contributors to this study include Henry Kapteyn, JILA physics professor, and JILA graduate students Peter Johnsen, Nicholas Jenkins, Yuka Esashi, Iona Binnie, and Michael Tanksalvala.
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Frequently Asked Questions (FAQs) about Ptychography Imaging
What is the new imaging method developed by CU Boulder researchers?
CU Boulder researchers have developed a new imaging method using doughnut-shaped light beams. This technique enhances the capabilities of ptychography, allowing for high-resolution imaging of small, regularly patterned structures like semiconductors, which were previously challenging to view with traditional microscopy.
How does the new ptychography technique work?
The new ptychography technique involves projecting doughnut-shaped beams of light onto a target and measuring how the light scatters. This method is different from traditional microscopes, which directly view objects. The scattered light patterns are then analyzed to create detailed images of the objects.
What are the potential applications of this new imaging method?
This new imaging method has significant potential applications in nanoelectronics and biological imaging. It can help improve the inner workings of nanoelectronic devices, including the miniature semiconductors in computer chips. It also holds promise for advancing the imaging of biological cells and other delicate structures.
What challenges does the new technique address in ptychography?
The new technique addresses a major challenge in ptychography: imaging highly periodic samples, such as objects with regularly repeating patterns. Traditional ptychography struggled with these types of samples, but the doughnut-shaped light beams create more complex scattering patterns that allow for detailed imaging of these structures.
What is the significance of the doughnut-shaped light beams in this method?
The doughnut-shaped light beams are crucial in this method as they enable the imaging of tiny and delicate structures, roughly 10 to 100 nanometers in size. These beams can capture accurate images without damaging the tiny electronics in the process, unlike some existing imaging tools like electron microscopes.
More about Ptychography Imaging
- CU Boulder Innovative Imaging
- Advancements in Ptychography
- Nanoelectronics Imaging Techniques
- Doughnut-Shaped Light Beams in Microscopy
- Ptychography in Microscopic Imaging
