New Way to Focus Light Beyond Normal Wavelengths to Reach Nanoscales in Length

Researchers at the Technion-Israel Institute of Technology have developed technology to compress light wavelengths fourfold, providing a way to focus light beyond normal wavelengths to reach nanoscales (a nanometer is a billionth of a meter) in length.

Using the metal-oxide-silicon (MOS) platform technology they developed for reducing the former “diffraction limit” of light wave length from 671 nanometers to 65 nanometers, a level at which “super-resolution” is possible, the researchers have made it possible to greatly advance the resolution quality for potential applications ranging from medical imaging to nanolithography (printing tiny electronic components).

“With increased brightness and resolution, microscopes will have increased accuracy at the molecular level,” says Prof. Guy Bartal of the Technion Department of Electrical Engineering. Nanometer-scale structures, such as the lab-on-a-chip device that can integrate several laboratory functions on a single chip, can be fabricated easier and at lower cost using lasers with shortened wavelengths. Bioimaging can also become more accurate and detailed with improved light resolution.

A paper outlining the characteristics and potential applications of the new platform was published in a recent issue of Optica (Vol 2 No. 2 pp 1045-1048), a publication of the Optical Society of America.

“The metal-oxide-silicon (MOS) platform we developed gives us the ability to shape, focus and control optical waves beyond their normal wavelengths,” said Prof. Bartal, who explained that as light wavelength is reduced, resolution becomes greater. “This means we can control the resolution and brightness of our focus, and also select its type and shape.”

The team’s super-resolution platform uses ultrathin commercial silicon membranes coated on one side with a thin layer of silicone oxide (Si02) and a metallic layer so as to set the diffraction limit in a controllable way using two-dimensional silicon-based wave guides. (Fig 2)

Not only does the new platform allow the researchers to successfully pass the diffraction limit, which was previously restricted to half the light’s wavelength, the new technology also “pushes” past that restriction without changing the color of the light.

“By providing resolution comparable to state-of-the-art methods, and while keeping the simplicity and flexibility of a diffraction-limited system, we offer the potential to develop a simple, easy-to-fabricate microscopy platform that is compatible with the mature silicon industry,” said Dr. Bergin Gjonaj, a senior researcher in the lab who developed a method to dynamically control the location of the nano-scale focusing.

The researchers’ ultimate goal is the creation of a more accessible device that is “on par” with current super-resolution techniques (which are still expensive, slow or energy-intensive) to make it possible to see biological activities at the molecular level.

The study was funded in part by the KLA-Tencor Corporation and the Israel Science Foundation (ISF) and supported by the Russell Berrie Nanotechnology Institute and Micro-Nano Fabrication Unit (MNFU) at the Technion-Israel Institute of Technology.

The Technion-Israel Institute of Technology is a major source of the innovation and brainpower that drives the Israeli economy, and a key to Israel’s renown as the world’s “Start-Up Nation.” Its three Nobel Prize winners exemplify academic excellence. Technion people, ideas and inventions make immeasurable contributions to the world including life-saving medicine, sustainable energy, computer science, water conservation and nanotechnology. The Joan and Irwin Jacobs Technion-Cornell Institute is a vital component of Cornell Tech, and a model for graduate applied science education that is expected to transform New York City’s economy.

American Technion Society (ATS) donors provide critical support for the Technion—more than $2 billion since its inception in 1940. Based in New York City, the ATS and its network of supporters across the U.S. provide funds for scholarships, fellowships, faculty recruitment and chairs, research, buildings, laboratories, classrooms and dormitories, and more.