A laser can make a detailed 3D image, but can it do it fast enough?
The answer, it turns out, depends on what you’re looking at.
A new study by a team at Cornell University shows that the use of a laser for a particular type of scanning method, called delocalized electron microscopy, is critical to making a 3D object visible.
The research, published in the Journal of Optics and Photonics, found that the new technique, which involves exposing electrons to a laser beam, produces better images than the previous method.
“The first step is to expose electrons to light, which is why it is so important to use the right type of laser,” said co-author Aaron Glynn, an associate professor in the College of Arts and Sciences’ Department of Physics.
“Our study shows that our previous method works best when we use a laser that is focused on a small area of the image,” Glynn added.
“We found that when we expose electrons at an angle, the images are sharp enough to be seen by the naked eye.
But when we apply the laser to the larger image, it produces a much sharper image.”
Glynn said delocalization is not just a technique for making 3D objects visible.
It can also make objects transparent, making them easier to read.
Delocalization, as the name implies, involves exposing a single electron to light.
This allows electrons to absorb the laser’s light.
But while this is an effective technique for imaging electrons, it is not as effective for scanning large areas of an object, such as a tree.
“Delocalized imaging, on the other hand, works for scanning an entire tree, and that’s what the authors wanted to find out,” Glynne said.
“To find out why, we needed to perform an experiment,” he said.
The researchers exposed a sample of leaves, or trunks, to a single laser beam and then studied how the electrons affected the image.
They found that electrons affected light transmission in a way that allowed them to make the images more detailed, but the electrons were also able to cause distortion, which was detrimental to the image resolution.
“If we expose more electrons at a time, then it gets a little harder to see the trees, but you can see the tree by moving the electron back and forth,” Gagan said.
In order to see what the problem was, the researchers focused on an area of an image that was 10 times larger than the other.
They focused on the area around the center of the tree.
In the image, they saw a lot of distortion because of the way electrons moved.
“It’s like a microscope, except you have to expose all the electrons at once,” Giannac said.
That was the key finding.
The authors found that their previous technique, focusing on an individual electron, had an image resolution of only about 20 microns, which could be resolved with a conventional microscope.
But in the delocalizing technique, they could see the electrons, which were a thousand times more distant than a single individual electron.
That finding is key, Gagan explained, because the electron that was exposed to the light was also a good candidate for the distortion.
“When you’re trying to see something as small as an electron, there’s a lot that can go wrong,” Gannon said.
“If you focus on an electron that is 10 times farther away than an individual atom, it’s going to get distorted, and this is a distortion that we found.”
Gannon and Glynn used a novel method to explore the effects of electron spin on the distortions they saw.
The authors showed that, while the electron spin of a single ion can change the shape of the electron, the spin of an electron with several spin configurations can actually alter the image of the atom.
“In this case, the electron spins are really tightly coupled,” Gannan said.
This means that the electron is moving at a constant speed with a constant direction of rotation.
“This is a pretty good test of how tight these spins are, and we find that these spin changes are very important in the distortion,” Gigan said.
Another important finding of the study was that when the researchers exposed the electron to the laser beam at different angles, the results varied from one electron to another.
That indicates that the light is not focused on just one electron, but a lot more electrons are moving around.
Glynn explained that when electrons are exposed to a beam that is aimed in different directions, they can interact with the light in the same way that they would when they are exposed in a straight line.
“That means that you see this large area of distortion when you focus the light on an entire electron,” Gahan said.
However, the light beam was not focused all at once.
Instead, it was focused in an arc of 100 microns that extends from the center to the edges of the beam