Generation of super-resolved optical needle and multifocal array using graphene oxide metalenses
2021-04-16
(Press-News.org) In a new publication from Opto-Electronic Advances; DOI https://doi.org/10.29026/oea.2021.200031, Researchers led by Professor Baohua Jia at Swinburne University of Technology, Victoria, Australia, Professor Cheng-Wei Qiu at National University of Singapore, Singapore and Professor Tian Lan at Beijing Institute of Technology, Beijing, China considered the generation of super-resolved optical needle and multifocal array using graphene oxide metalenses.
Ultrathin and lightweight, metalenses are becoming increasingly significant for their use in photonic chips, biosensors and micro imaging systems such as smart phone cameras.
Compared to conventional lenses, metalenses can improve the image quality of current cameras, by enhancing resolution and removing spherical and chromatic aberrations. A single ultrathin (less than the thickness of 1/100 of a human hair) metalens element can be used instead of the multiple element imaging systems required by conventional lenses. Due to the unique light-matter interaction in a confined 2D plane, 2D materials are ideal for use with metalenses, further reducing the required thickness of the lens. 2D Graphene family materials, for example graphene oxides, are air-stable, have many applications and are low-cost and easy to fabricate in large scale. They remain stable in extreme environments, for example lower earth orbit in aerospace, so have potential use in satellites replacing the current bulky lenses and improving imaging quality and lowering launch costs.
The authors of this article developed 200 nm thick graphene oxide metalenses to generate specialized focal intensity distributions. The graphene oxide metalenses have the capability of controlling light amplitude (i.e., transparency of the lens) and phase (refractive index and thickness of the lens) simultaneously. This differs from other metalenses, which introduce the modulations through multi-step nanofabrication or multilevel of nano-elements, the modulations of graphene oxide lenses are locally introduced by the laser photo-reduction process, which converts graphene oxide to graphene material. During the reduction process, the material becomes thinner and has a higher refractive index and absorption. Based on the simultaneous phase and amplitude modulations, the authors demonstrate precise control of the focal intensity distributions by creating a super-resolved ultra-long optical needle and an axial multifocal array, which are extremely challenging for other metalenses.
Graphene oxide metalenses will find broad applications in integrated photonics and compact photonic systems, including microscopic imaging, optical manipulation and photonic chips, and can be integrated on microfluidic chips to form lab-on-a-chip biophotonic devices. This research forms a basis for the development of graphene-based ultrathin integratable photonic devices and paves the way for broader applications, such as replacing current cell phone camera lens potentially allowing a reduction in the thickness of current cell phones.
INFORMATION:
Article reference: Hongtao Wang, Chenglong Hao, Han Lin, Yongtian Wang, Tian Lan, Chengwei Qiu and Baohua Jia, Generation of super-resolved optical needle and multifocal array using graphene oxide metalenses, Opto-Electronic Advances, 2021, ISSN 2096-4579, https://doi.org/10.29026/oea.2021.200031
Keywords: femtosecond laser reduction; graphene oxide; metalens; multifocal spots; optical needle
Led by Professor Baohua Jia, the Centre for Translational Atomaterials (CTAM) at Swinburne University of Technology, Victoria, Australia focuses on fundamental research of atomic material (atomaterials) design, engineering as well as the development of transformative technologies of such novel materials. With 70 research staff and students, CTAM is the world's first dedicated centre for atomaterial research and translation. Current research areas include intelligent atomic structure design and synthesis, in-situ characterization, functional device design and fabrication, structure design and optimization as well as device engineering and translation.
Opto-Electronic Advances (OEA) is a high-quality, open access, peer reviewed research journal that is published by The Institute of Optics and Electronics, Chinese Academy of Sciences. OEA provides a platform for researchers, academicians, professionals, practitioners, and students to impart and share knowledge in the form of high quality empirical and theoretical research papers covering the topics of optics, photonics and optoelectronics.
Since its launch in March 2018, OEA has expanded into a monthly publication schedule. From 2020 OEA is indexed by Science Citation Index Expanded (SCIE) and SCOPUS. From the current Web of Science (WoS) data, OEA expects that the June 2021 Journal Citation Report (JCR) should show that the journal has an Impact Factor of about 10.
More information: http://www.oejournal.org/J/OEA.html
Editorial Board: http://www.oejournal.org/J/OEA/EditorBoard
All issues available in the online archive (http://www.oejournal.org/J/OEA/Article/AllIssues).
Submissions to OEA may be made using ScholarOne (https://mc03.manuscriptcentral.com/oea).
ISSN: 2096-4579
CN: 51-1781/TN
Contact Us: oea@ioe.ac.cn
Twitter: @OptoElectronAdv
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-04-16
In most living animals, egg cells are vastly larger than sperm cells. In humans, for example, a single egg is 10 million times the volume of a sperm cell.
In a new study, Northwestern University researchers found that competition and natural selection drove this curious size discrepancy.
Using mathematical modeling, the researchers considered a time very early in evolution when primordial species reproduced using external fertilization. In the model, bigger reproductive cells, or gametes, presented a competitive edge because they could hold more nutrients for a potential zygote. Smaller gametes, however, required fewer resources to make, which put less stress on the parent.
"Organisms either needed to produce the biggest gametes with the most provisions ...
2021-04-16
When temperatures drop below zero degrees Celsius, water turns to ice. But does everything actually freeze if you just cool it down enough? In the classical picture, matter inherently becomes solid at low temperatures. Quantum mechanics can, however, break this rule. Therefore, helium gas, for example, can become liquid at -270 degrees, but never solid under atmospheric pressure: There is no helium ice.
The same is true for the magnetic properties of materials: at sufficiently low temperatures, the magnetic moments known as 'spins', for example, arrange themselves in such a way that they are oriented opposite/antiparallel to their respective neighbors. One can think of this as arrows pointing alternating up and down along a chain or in a checkerboard pattern. It ...
2021-04-16
Snow cover in the Alps has been melting almost three days earlier per decade since the 1960s. This trend is temperature-related and cannot be compensated by heavier snowfall. By the end of the century, snow cover at 2,500 meters could disappear a month earlier than today, as simulations by environmental scientists at the University of Basel demonstrate.
Global warming demands huge adjustments in tourism, hydropower generation and agriculture in alpine areas. But the fauna and flora also have to adapt to rising temperatures. By the end of the century, ...
2021-04-16
If you are exposed to silica (quartz) dust at work - e.g. from working with concrete and granite - you have a greater risk of certain types of rheumatic disease. This is shown by results from Aarhus University and Aarhus University Hospital, which have just been published in the International Journal of Epidemiology.
Exposure to silica dust at work, which is the case especially at workplaces within construction and industry, may lead to autoimmune rheumatic diseases. Photo: Unsplash.
Exposure to silica dust at work, which is the case especially at workplaces within construction and industry, may lead to autoimmune rheumatic diseases. Photo: Unsplash.
As the research results from Aarhus University show, exposure to ...
2021-04-16
The leading newspapers in two nuclear waste management forerunner countries, Finland and France, fulfil their "watchdog" roles in highly distinct ways. The Finnish Helsingin Sanomat (HS) tends to reproduce government and industry framings, whereas Le Monde cherishes its role as an independent critic of the powers that be. These differences reflect distinct cultural, political and media traditions in the two countries.
"The critical watchdog model works in a liberal democracy such as the French, based on mistrust towards the governing elites. But would it backfire in Finland by undermining the very institutional trust that the Nordic democracies have been built upon throughout history?" asks the first author of the article, Research Fellow Markku Lehtonen from the Department of Humanities ...
2021-04-16
A new study has shown that underweight and overweight women are at a significantly higher risk of experiencing recurrent miscarriages compared to those of average weight.
A research team led by the University of Southampton assessed the link between women's lifestyle and risk of recurrent pregnancy loss, defined as women having two or more consecutive early miscarriages. The systematic review and meta-analysis study has been published in the journal Scientific Reports.
Miscarriage is the most common complication of early pregnancy, affecting 15 - 20% of all pregnancies. Recurrent pregnancy loss is a complex disease and although often attributed to numerous medical factors and lifestyle influences, the cause is deemed "unexplained" ...
2021-04-16
Tokyo, Japan - Leukemias are debilitating cancers of the hematopoietic or blood-forming cells of the bone marrow. Now, researchers at Tokyo Medical and Dental University (TMDU) describe an ingenious strategy against chronic myelomonocytic leukemia (CMML) wherein an antibody-drug conjugate (ADC) comprising a cytotoxic drug payload linked to an antibody that selectively targets specific cell lines effectively blocks malignant cell proliferation at source.
Hematopoietic stem and progenitor cells (HSPCs) continually differentiate into the entire panoply of blood cells, as many as 500 ...
2021-04-16
Since fast radio bursts (FRBs) were first discovered over a decade ago, scientists have puzzled over what could be generating these intense flashes of radio waves from outside of our galaxy. In a gradual process of elimination, the field of possible explanations has narrowed as new pieces of information are gathered about FRBs - how long they last, the frequencies of the radio waves detected, and so on.
Now, a team led by McGill University researchers and members of Canada's CHIME Fast Radio Burst collaboration has established that FRBs include radio waves at frequencies lower than ever detected before, a discovery that redraws the boundaries for theoretical astrophysicists trying to put their finger on the source of FRBs.
"We ...
2021-04-16
WHAT:
The experimental antiviral drug MK-4482 significantly decreased levels of virus and disease damage in the lungs of hamsters treated for SARS-CoV-2 infection, according to a new study from National Institutes of Health scientists. SARS-CoV-2 is the virus that causes COVID-19. MK-4482, delivered orally, is now in human clinical trials. Remdesivir, an antiviral drug already approved by the U.S. Food and Drug Administration for use against COVID-19, must be provided intravenously, making its use primarily limited to clinical settings.
In their study, published in the journal ...
2021-04-16
Artificial intelligence (AI) has sped up the process of detecting flooded buildings immediately after a large-scale flood, allowing emergency personnel to direct their efforts efficiently. Now, a research group from Tohoku University has created a machine learning (ML) model that uses news media photos to identify flooded buildings accurately within 24 hours of the disaster.
Their research was published in the journal Remote Sensing on April 5, 2021.
"Our model demonstrates how the rapid reporting of news media can speed up and increase the accuracy of damage mapping activities, accelerating ...
LAST 30 PRESS RELEASES:
[Press-News.org] Generation of super-resolved optical needle and multifocal array using graphene oxide metalenses
