Looking through binoculars from the bleachers at a baseball game, at an eagle as it alights on a distant tree or at a constellation in a cloudless night are all much easier with a clear lens. A smudge, crack or even a hair on the lens can make that long-distance gazing considerably more challenging, as the images become blurry and our eyes struggle to interpret the difference between what’s out there and the defect in our binoculars.

The same holds true for radiation detectors. Constructed with bars of crystals, the detectors have applications in everything from medical imaging to see tumors to peering deep into the universe for signature radiation signals to detecting the movement of nuclear materials to help prevent an attack or accident.

A significant challenge with these detectors has been the defects that appear as the crystal grows. Scientists work on two fronts to deal with these imperfections: They improve the quality of the crystals, and they develop ways to compensate for the imperfections.

At Brookhaven National Laboratory, physicist Aleksey Bolotnikov has made significant contributions to improving detector performance despite the flaws in the crystal.

“We veto the interactions in the ‘bad’ regions of the crystals,” Bolotnikov explained.

Working with a team of scientists at BNL, including Giuseppe Camarda, Utpal Roy, Anwar Hossain and Ge Yang, Bolotnikov has been able to measure the coordinates of these defects with high accuracy. This allows the researchers to improve the detecting capability and reduce the cost by increasing the acceptance rates of the crystals.

Recently, Bolotnikov authored a paper in Applied Physics Letters in which he increased the size and thickness of the crystals. The thicker crystals are important in detecting weak sources.

Bolotnikov has “been able to establish new records for the thickness of semiconductor gamma-ray detectors operating at room temperature,” offered Ralph James, who heads Bolotnikov’s department and has collaborated with him ever since he arrived 20 years ago. “This is a critical step in the move to replace many traditional radiation-sensing instruments used today.”

The biggest market for these detectors with thicker crystals is in nuclear medical instruments for oncology and cardiology, James said.

Bolotnikov explained that the team at BNL combines researchers with expertise in a range of areas. Roy grows the crystals, while a group from the instrumentation division led by Gianluigi De Geronimo facilitates the work as a “top expert in readout electronics.” By tapping into his expertise in nuclear physics and nuclear engineering, Bolotnikov is  also able to design and develop new detectors.

James credits his colleague with significant advances in detector technology. “His new position-sensitive device design has rendered outstanding results that have approached the theoretical limits for energy resolution,” James said.

The work of Bolotnikov and the team has earned them national recognition. Bolotnikov was a part of three R&D Magazine’s R&D 100 Awards, in 2006, 2009 and 2014.

Last fall, he received the Room Temperature Semiconductor Detector Scientist Award from the Institute of Electrical and Electronics Engineers. The award recognized a scientist who had done the most to impact room temperature semiconductor detectors and could be given either for a lifetime of work or for a single accomplishment.

The award is “well earned,” James said. Bolotnikov’s votes among the awards committee “surpassed others by far.”

Like other members of his team, James said Bolotnikov works most waking hours. “I can count on a quick response from him via emails during the evenings,” James said.

Born in a small city near Moscow, Bolotnikov first came to Long Island around 1991. He now lives in Setauket with his wife Mila, who is a teacher for North Shore Montessori. His daughter Dasha works at BlackRock, while his son Vassili works for a small management company affiliated with Stony Brook Hospital.

Bolotnikov, who said he enjoys his work, suggested that the effort to improve technology generates new ideas, which “creates the new background or basis for writing proposals for the next cycle of work.”

Bolotnikov continues to work on increasing the size of the crystals in the detectors. At some point, the larger sizes can become prohibitively expensive. An alternative, he suggested, is to use gamma-ray focusing optics, concentrating gamma rays coming from large areas toward a reasonably sized detector. “This, he said, “is a new horizon.”

If imitation is the highest form of flattery, there should be plenty of blushing moths. A group of scientists is working on a new way to create a structure similar to the moth eye, albeit with several important differences, to build a better solar cell.

Unlike human eyes, the compound moth’s eyes have a collection of miniature posts across their surface.

These posts allow the moth to absorb a wide range of light without reflecting it back. This prevents the “moth in the headlights” appearance, enabling the insect to blend in without sending a reflection predators might notice.

While Lord Rayleigh worked out the mathematics for why the moth eye geometry eliminates reflection in the 1800s, a team at Brookhaven National Laboratory has come up with a new approach to creating an anti-reflective silicon.

“Our advance is in coming up with a tricky new way” to make a silicon surface that absorbs instead of reflects light, said Chuck Black, a scientist and group leader at the Center for Functional Nanomaterials at BNL. “We think it has practical advantages in applying this” to things like solar cells or even, some day, anti-reflective windshields on cars or windows in buildings.

Companies have been using multilayer coatings to increase the ability of silicon solar cells to absorb light. By etching a nanoscale texture onto the material, researchers including Black and Atikur Rahman, a postdoctoral researcher, were able to create an anti-reflective surface that works as well as multilayer coatings, while outperforming single antireflective film by about 20 percent.

The researchers coated the top of a silicon solar cell with a substance Black has worked with for more than 15 years, called a block copolymer. The advantage to this substance is that it can self-organize into a surface pattern with dimensions of only about 10 nanometers. This pattern enabled the development of posts that are similar to those of a moth’s eyes, even though the features in their structures are much smaller than those in the insect eye.

The challenge in trying to reduce reflections is that sunlight has a wide range of colors at different wavelengths. Substances designed to absorb one color won’t be as effective at capturing a different one.

That’s where the moth enters the picture.

“Nature has learned how to create this anti-reflection,” by using spikes, Black said. “This promotes anti-reflection not just in one but in all wavelengths of light.”

The way this works is somewhat akin to the proverbial frog in a pot of water. In the frog story, a frog sitting in a pot of water that slowly heats up doesn’t jump out of the water even when it’s boiling because it’s adjusted to the changing temperature. Similarly, these spikes draw light of different wavelengths in because the distances between them are all smaller than the wavelength of light. The light effectively reacts to their average properties, Black explained.

When the light travels through these spikes, which are not cylindrical but, rather are thinner at the top and flair at the bottom, it reacts as if it hits something that is a combination of something small and insignificant and air. As the light travels towards the silicon surface, it interacts less with air and more with the spike, where it becomes absorbed by the thicker base before it can reflect back out.

“You’re softening this transition between air and whatever you’re trying to couple the light into,” Black said. Instead of a sharp boundary between the air the light is traveling through and the surface, the spikes ease that interaction, gradually capturing the light.

To demonstrate its effect, Black held a small photograph of his lab above a reflecting surface in which a small square is coated with the anti-reflective material. In the reflection, the square with the anti-reflective substance appears black.

Black and Rahman, who was the lead author on the study, published their results in Nature Communications. They don’t know whether this approach is more economical or efficient than the current multilayer coating for solar cells. They are working with external partners to understand the economic or performance advantages of this approach, he said.

Black and his wife Theresa Lu, who is a physician scientist at the Hospital for Special Surgery, live in Manhattan with their two primary school children, Marina and Charlotte.

As for his work, Black and Rahman filed a patent for this technology last year. “It’s something we’re very proud of,” he said.