IIT Guwahati and Columbia University Unveil Optical Driving Process for Nanopatterns

IIT Guwahati and Columbia University have collaborated to pioneer a revolutionary nanopatterning technique employing an uncomplicated tabletop IR laser. Check details here 

The Indian Institute of Technology (IIT) Guwahati and Columbia University, USA, scientists have developed a nanopatterning method using a simple tabletop IR laser. Dr. Rishi Maiti, Assistant Professor in the Department of Physics at IIT Guwahati and former post-doctoral scientist from Alexander Gaeta’s quantum and non-linear photonics group, has published the research findings in the prestigious journal, Science Advances.

Nanopatterning involves creating patterns on materials at the nanometer scale, which is a hundred thousand times smaller than the width of a human hair. This technique enables the fabrication of nano-scaled optical elements and polariton cavities, essential for advanced devices like light detectors, solar cells, lasers, and light-emitting diodes.

Traditional nanoscale patterning methods require specialized equipment and infrastructure, such as clean rooms for electron beam lithography machines, or techniques involving high local heating and plasma due to the direct writing. In search of a more accessible and cost-effective alternative, the multi-institutional team adopted a less strenuous process called "optical driving," leveraging the resonance frequency principle in materials.

Unzipping Technique 

Using a technique known as "unzipping," the researchers successfully cleaved hexagonal boron nitride with an infrared laser. This process created atomically sharp lines across the sample, with widths of only a few nanometers. The use of laser wavelengths at 7.3 micrometres enabled clean lattice breaks, producing controllable nanostructures.

The researchers then "unzipped" two parallel lines, forming a nano-dimensional cavity capable of trapping phonon-polaritons—unique quasi-particles arising from the interaction of light and vibrations. These trapped particles can concentrate light into sub-nanometric spots, offering significant potential for highly sensitive mid-infrared sensing and spectroscopy.

Emphasising the significance of this breakthrough, Dr. Rishi Maiti, Assistant Professor, Department of Physics, IIT Guwahati and co-author of this work, said, "This novel nano-patterning technique using optically induced strain opens doors to a myriad of possibilities in nanoscience and technology. Its simplicity and effectiveness mark a significant advancement in the field, with far-reaching implications across various industries.”

Read More 

• IIT Guwahati and NSDC Introduce Daksh Gurukul Skill Academy for Credit Programs
• IIT Guwahati Engineers Make Strides with High-Performance Materials for Future Supercapacitors