Nav: Home

Color superlensing to assist in surpassing diffraction barrier

January 03, 2020

The research was supported by a Russian Science Foundation's grant under the title "Synthesis and research of a new class of nanocomposite ceramics with degenerate dielectric permeability for opto-plasmonic applications."

A metalens described in the article is a thin composite metal-dielectric film placed on a dielectric substrate; the width is several dozen nanometers.

"The light has a wave nature, so there is a diffraction limit which confines the resolution of traditional optical microscopy," explains Kharintsev. "Our metalens is an optical device capable of surpassing that diffraction limit. Such a solution paves way for using optical technologies in nanoscale integral circuits and sensors."

The ultra-high resolution is based on an unusual behavior of the metalens in optical and infrared ranges.

"The material part of the dielectric constant oscillates near zero. This property can be used to enhance stimulated Raman scattering of light in a spatially limited medium illuminated by low-intensity continuous laser light. For most materials found in nature, nonlinear effects are weak, and to observe them it is necessary to increase the length of the medium (for example, using optical fibers) and / or to increase the laser pump power (using high-power pulsed lasers).

"We used a 50 nm thick titanium oxy nitride (TiON) film as a disordered nonlinear medium. The film was synthesized by magnetron sputtering and subsequent oxidation in air. As a result of a two-stage procedure, metal (TiN) and dielectric (TiO2) nanoparticles were formed in the film. An increase in the amplitude of the Stokes wave in a TiN / TiO2 film occurs due to the enhancement of the cubic susceptibility because of localized plasmon resonance and a small refractive index of the effective medium. Such metal-insulator nanocomposite films having several epsilon-near-zero frequencies in the visible and infrared ramges have found application in creating broadband metal technologies providing resolution beyond the limits of light diffraction," adds the author.

Kazan University employees have succeeded in visualizing 40 nm multiwall carbon nanotubes scattered along the surface of the metalens created by them, and the resolution was below 100 nm.

"Nanocomposite epsilon-near-zero film works as a surface-enhanced Raman scattering substrate, and it helps not only enhance the scattered signal, but also achieve beyond-diffraction resolutions. Metalenses and ENZ films can be used to create broadband absorbers for solar panels," concludes Dr. Kharintsev.

Kazan Federal University

Related Research Articles:

More Research News and Research Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at