June 16, 2024

Simple Silicon Coating Solves Long-Standing Optical Challenge for Powerful, Ultrafast Laser Pulses

This chromatic dispersion issue has actually afflicted optical scientists for decades. Today, the majority of solutions involve additional components that increase the size and bulk of optical devices..
Now, scientists at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), in partnership with Graz University of Technology, have established a silicon finish that, when applied to the surface area of a glass lens, can neutralize the impacts of dispersion..
The research study is published in Nature Communications..
Scanning electron microscopic lense photo of the compressor with 158 nm nanopillar diameter. Credit: Harvard SEAS.
” Our flexible method can be quickly implemented in optical setups and conventional optics and be adjusted to various spectral regions and applications,” said Federico Capasso, the Robert Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS and senior author of the study..
The ultra-thin covering utilizes precisely created silicon pillars that briefly record and hold traffic signal before re-emitting it. This short-lived hold enables the slower-moving blue light to capture up..
” Our coating counteracts the dispersive impacts of transparent products, acting as a speed bump for red light and averaging out the speed of each wavelength of light,” stated Marcus Ossiander, a postdoctoral research study fellow at SEAS and very first author of the paper..
The scientists evaluated the covering by reducing laser pulses to just a couple quadrillionths of a 2nd. The nanopillar silicon coating was made utilizing the exact same industrial lithography tools as industrial semiconductors, making it simple to rapidly use these finishings to existing optical elements and broaden the applicability of femtosecond laser pulses..
” Now, anyone can buy a lens, put the covering on and utilize the lens without stressing over dispersion,” stated Ossiander. “This approach can be the basis for an array of anti- or non-dispersive optics.”.
Recommendation: “Slow light nanocoatings for ultrashort pulse compression” by M. Ossiander, Y.-W. Huang, W. T. Chen, Z. Wang, X. Yin, Y. A. Ibrahim, M. Schultze and F. Capasso, 11 November 2021, Nature Communications.DOI: 10.1038/ s41467-021-26920-6.
The research study was co-authored by Y. W. Huang, W.T. Chen, Z. Wang, X. Yin, Y. A. Ibrahim, and M. Schultze. It was supported in part by the Office of Naval Research (ONR), under the MURI program, grant no.

The research study was co-authored by Y. W. Huang, W.T. Chen, Z. Wang, X. Yin, Y. A. Ibrahim, and M. Schultze. It was supported in part by the Office of Naval Research (ONR), under the MURI program, grant no. N00014-20-1-2450, by the Air Force Office of Scientific Research (AFOSR), under grant no. FA95550-19-1-0135 and the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the NSF under award no. ECCS-2025158.

Brand-new technique broadens the application of powerful, ultrafast laser pulses.
Quick bursts of laser light, lasting less than a trillionth of a second, are used in a range of applications today. These ultrashort laser pulses have actually enabled scientists to observe chain reactions in real-time, image fragile biological samples, build accurate nanostructures, and send out long-distance, high-bitrate optical interactions..
Any application of ultrashort laser pulses in the noticeable spectrum must get rid of a fundamental difficulty– red light journeys quicker than blue light through transparent products like glass. When an ultrashort laser pulse passes through a glass lens, the firmly packed wavelengths of light different, destroying the usefulness of the beam.

By Harvard John A. Paulson School of Engineering and Applied Sciences
January 19, 2022