Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Machine learning helps improving photonic applications

28.09.2018

Photonic nanostructures can be used for many applications, not just in solar cells, but also in optical sensors for cancer markers or other biomolecules, for example. A team at HZB using computer simulations and machine learning has now shown how the design of such nanostructures can be selectively optimised. The results are published in Communications Physics.

Nanostructures can increase the sensitivity of optical sensors enormously – provided that the geometry meets certain conditions and matches the wavelength of the incident light. This is because the electromagnetic field of light can be greatly amplified or reduced by the local nanostructure.


Here, stripes with local field maxima are formed, so that quantum dots shine particularly strongly.

Carlo Barth / HZB

The HZB Young Investigator Group “Nano-SIPPE” headed by Prof. Christiane Becker is working to develop these kinds of nanostructures. Computer simulations are an important tool for this. Dr. Carlo Barth from the Nano-SIPPE team has now identified the most important patterns of field distribution in a nanostructure using machine learning, and has thereby explained the experimental findings very well for the first time.

Quantum dots on nanostructures

The photonic nanostructures examined in this paper consist of a silicon layer with a regular hole pattern coated with what are referred to as quantum dots made of lead sulphide. Excited with a laser, the quantum dots close to local field amplifications emit much more light than on an unordered surface. This makes it possible to empirically demonstrate how the laser light interacts with the nanostructure.

Ten different patterns discovered by machine learning

In order to systematically record what happens when individual parameters of the nanostructure change, Barth calculates the three-dimensional electric field distribution for each parameter set using software developed at the Zuse Institute Berlin. Barth then had these enormous amounts of data analyzed by other computer programs based on machine learning.

“The computer has searched through the approximately 45,000 data records and grouped them into about ten different patterns”, he explains. Finally, Barth and Becker succeeded in identifying three basic patterns among them in which the fields are amplified in various specific areas of the nanoholes.

Outlook: Detection of single molecules, e.g. cancer markers

This allows photonic crystal membranes based on excitation amplification to be optimised for virtually any application. This is because some biomolecules accumulate preferentially along the hole edges, for example, while others prefer the plateaus between the holes, depending on the application.

With the correct geometry and the right excitation by light, the maximum electric field amplification can be generated exactly at the attachment sites of the desired molecules. This would increase the sensitivity of optical sensors for cancer markers to the level of individual molecules, for example.

The software used as well as the data can be downloaded free.

Originalpublikation:

Published in Communications Physics (2018). “Machine learning classification for field distributions of photonic modes”, Carlo Barth & Christiane Becker

DOI:10.1038/s42005-018-0060-1

Dr. Antonia Rötger | Helmholtz-Zentrum Berlin für Materialien und Energie GmbH

More articles from Life Sciences:

nachricht Elusive compounds of greenhouse gas isolated by Warwick chemists
18.09.2019 | University of Warwick

nachricht Study gives clues to the origin of Huntington's disease, and a new way to find drugs
18.09.2019 | Rockefeller University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Happy hour for time-resolved crystallography

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.

The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.

Im Focus: Modular OLED light strips

At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.

Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...

Im Focus: Tomorrow´s coolants of choice

Scientists assess the potential of magnetic-cooling materials

Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....

Im Focus: The working of a molecular string phone

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Potsdam (both in Germany) and the University of Toronto (Canada) have pieced together a detailed time-lapse movie revealing all the major steps during the catalytic cycle of an enzyme. Surprisingly, the communication between the protein units is accomplished via a water-network akin to a string telephone. This communication is aligned with a ‘breathing’ motion, that is the expansion and contraction of the protein.

This time-lapse sequence of structures reveals dynamic motions as a fundamental element in the molecular foundations of biology.

Im Focus: Milestones on the Way to the Nuclear Clock

Two research teams have succeeded simultaneously in measuring the long-sought Thorium nuclear transition, which enables extremely precise nuclear clocks. TU Wien (Vienna) is part of both teams.

If you want to build the most accurate clock in the world, you need something that "ticks" very fast and extremely precise. In an atomic clock, electrons are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

AI for Laser Technology Conference: optimizing the use of lasers with artificial intelligence

29.08.2019 | Event News

 
Latest News

Stroke patients relearning how to walk with peculiar shoe

18.09.2019 | Innovative Products

Statistical inference to mimic the operating manner of highly-experienced crystallographer

18.09.2019 | Physics and Astronomy

Scientists' design discovery doubles conductivity of indium oxide transparent coatings

18.09.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>