Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


On-chip spin-Hall nanograting for simultaneously detecting phase and polarization singularities


Optical singularities are key elements in modern optics and have been widely researched. In particular, phase and polarization singularities have been manipulated in various applications, such as imaging and metrology, nonlinear optics, optical tweezers, sensing, quantum information, and optical communication.

In theory, both singularities can be detected simultaneously if one can detect the topological charge and photon spin at the same time. Several methods have been proposed to detect the topological charge of the OAM in recent years, including holography, metasurfaces, optical transformation, and photonic circuits.

Schematic of the designed structure under illumination of two OAM beams with different polarization states and topological charges

Credit: Fu Feng, Guangyuan Si, Changjun Min, Xiaocong Yuan, Michael Somekh

However, these methods have drawbacks including the need to align the beam precisely with the structure, the need for complex detection processes, such as near-field microscopy, and the low diffraction efficiencies of some elements.

These drawbacks strongly limit their applications in new optical systems with optical fibres or integrated on-chip devices.

In a new paper published in Light Science & Application, a team of scientists, led by Professor Changjun Min, Xiaocong Yuan, Mike Somekh from Nanophotonics Research Center, Shenzhen Key Laboratory of Micro-Scale Optical Information Technology, Shenzhen University, Shenzhen 518060, China and co-workers have developed an on-chip plasmonic spin-Hall nanograting for simultaneously detecting phase and polarization singularities.

They have designed a symmetry-breaking nanograting structure first to unidirectionally launch the SPP wave according to the sign of the topological charge of the incident wave. The propagation angle of the generated SPP increases with the value of the topological charge.

The topological charge value of the incident beam can be accurately determined by placing an output coupling grating on both sides of the nanograting to couple the generated SPP wave to the far field and analysing the far-field optical microscopy image. Additionally, a spin-Hall structure is integrated onto the nanograting so that the nanograting can respond to the spin of the incident beam.

This combined structure directionally couples the incident OAM beam to different positions depending on the polarization and topological charge of the beam. It is proved experimentally that the structure detects the polarization singularity and phase singularity of the incident CVB beam simultaneously.

This device is very promising for achieving a highly compact photonic integrated circuit. These scientists summarize the operational principle of their structure:

"We design a SPP based meta-surface which can detect simultaneously phase and polarization singularities of the incident wave for two purposes in one: (1) to rapidly and simultaneously detect the phase and polarization singularities with single shot image; (2) to enable optical communication with photonics singularities of electromagnetic waves."

"This device is very promising for achieving a highly compact photonic integrated circuit. It has shown great potential in large-scale photonic integrated circuits and would benefit diverse applications such as optical on-chip information processing and optical communications. We are now trying to intergrate an additional coupound phase modulation structure onto the device to cancel the diffraction effect of the SPP wave during generation. This would further enhance the resolution and detection limit of the system." they added

"The presented technique can be used for new generation of optical communication. As photonic singularities are new degree of freedom which can carry far more information compare to what the intensity modulation, frequency modulation we use now. The tiny volum of the device and its capacity of information processing will open a new gate to modern communication in both classic regime and quantum regime." The scientists forecast.

Fu Feng | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Manifestation of quantum distance in flat band materials
05.08.2020 | Institute for Basic Science

nachricht First radio detection of an extrasolar planetary system around a main-sequence star
04.08.2020 | Max-Planck-Institut für Radioastronomie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: New Strategy Against Osteoporosis

An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.

Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...

Im Focus: AI & single-cell genomics

New software predicts cell fate

Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...

Im Focus: TU Graz Researchers synthesize nanoparticles tailored for special applications

“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.

Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...

Im Focus: Tailored light inspired by nature

An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.

Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...

Im Focus: NYUAD astrophysicist investigates the possibility of life below the surface of Mars

  • A rover expected to explore below the surface of Mars in 2022 has the potential to provide more insights
  • The findings published in Scientific Reports, Springer Nature suggests the presence of traces of water on Mars, raising the question of the possibility of a life-supporting environment

Although no life has been detected on the Martian surface, a new study from astrophysicist and research scientist at the Center for Space Science at NYU Abu...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

“Conference on Laser Polishing – LaP 2020”: The final touches for surfaces

23.07.2020 | Event News

Conference radar for cybersecurity

21.07.2020 | Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

Latest News

Manifestation of quantum distance in flat band materials

05.08.2020 | Physics and Astronomy

Discovery shows promise for treating Huntington's Disease

05.08.2020 | Health and Medicine

Rock debris protects glaciers from climate change more than previously known

05.08.2020 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>