Author Archives: Megan

1. Future Horizons for Photonics Research 2030 and beyond report released

   September 7, 2020 12:11 pm Leave a Comment

   A ground breaking horizon scanning report on the future of photonics research 2030 and beyond has been released by the Photonics Leadership Group and the All-Party Parliamentary Group in Photonics and Quantum.  The PLG brought together 26 of the UK’s leading photonics researchers from 20 different institutions to ask “what will be the focus of photonics research a decade and more from now?”

   View the report here 

   Recognising all R&D takes place in an ever developing socio-economic environment, the report also identifies nine major challenges that photonics will have a key role in addressing. Ranging from future mobility, healthy-aging and real-time secure communications to responsive manufacturing, food production and defence; it is clear that photonics not only already makes a major contribution to society, but will be absolutely instrumental in addressing the challenges of the future.

   The report makes 7 clear recommendations to translate the identified topics into funded research balanced across all domains.  The recommendations also call on those working in vertical markets to integrate this future vision into their technology roadmaps to ensure the very best and most advance photonics is rapidly pulled through into applications for the benefit of all.

   Described by some of the UK’s leading photonics researchers as “an excellent and timely report” capturing how much  “it is an exciting time for the field”, it is hoped the highlighted topics stimulate discussion on the future directions for photonics as well as inspire the next generation of researchers.

   Co-director of London Light Anatoly Zayats said “It is very important for the photonics community to have a global view of the challenges, trends and needs of photonic science and technology in the years to come. We hope very much the document will provide the government and industry with understanding where photonics goes and its role in the future of our society.”

   John Lincoln, Chief Executive of the PLG said “It has been an incredible cathartic and inspirational exercise to take a break from all of our current challenges and look to the future and consider the huge diversity of photonics still to be discovered.”

2. What is on the Horizon for Future Photonics Research

   April 30, 2020 11:37 am Leave a Comment

   The Photonics Leadership Group have published the preliminary outputs of a recent workshop that comprised of twenty-five of the leading photonics researchers in the UK.

   The academics were asked ‘What is on the Horizon for Future Photonics Research?’ to generate a picture of where photonics research will be focused in ten years time. The raw output of that workshop is captured in the summary of seventy topics identified as offering significant potential for future investigation (shown below).

   The detailed outputs will be published in a full report in the summer of 2020.

   You can read more on the Photonics Leadership Group webpage.

   

   Click to see full-sized image

    

    

3. Nobel laureate tells how to beat his own award-winning imaging technique

   February 20, 2020 10:28 am Leave a Comment

   In the 1990s an optical imaging technique emerged that overturned the “diffraction limit”, which for over a century had defined the maximum achievable resolution an optical microscope could achieve at around half the wavelength of the illuminating light. At King’s College London’s Wheatstone Lecture 2020, attendees heard from Stefan Hell, the Nobel laureate who had developed the technique – stimulated emission depletion microscopy (STED). In his talk he described a new kid on the block in the world of optical imaging techniques that can beat the resolution of STED by a further factor of 10.

   Hell began his talk with an overview of his STED technique and two others developed in the 2000s – photo-activated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM) – that together led to the award of the 2014 Nobel Prize for Chemistry to Eric Betzig, Stefan W. Hell and William E. Moerner “for the development of super-resolved fluorescence microscopy.”

   “I’m still struggling with this chemistry thing,” smiled Hell “I don’t know much about chemistry.” Despite the modesty of his claim, as his talk pointed out all these super-resolution techniques hinge on the use of fluorescing molecules that stain the sample being imaged. The chemistry becomes important for choosing the right molecules that will fluoresce with the right behaviour – emitting photons and “bleaching” or ceasing to emit them when flooded with light, only in ways that allow the techniques to work. Nonetheless he was true to his word that there wouldn’t be too much chemistry in the talk, giving instead a tour de force of the physics behind these techniques.

   Both STED and PALM/STORM illuminate a diffraction-limited region to excite the molecules there to fluoresce. However, STED uses an additional, for example, doughnut-shaped beam to deplete emissions from part of this region, while PALM and STORM use the stochastic nature of the molecules’ fluorescence and bleaching to build up a picture with a resolution that beats the diffraction limit. Both techniques should be capable of resolution at the molecular level but as Hell pointed out, in practice they are limited to a resolution of ten times this at around 20 nm. This is still ten times better than diffraction-limited optical microscopy can achieve, but he was keen to resolve molecular level detail, which is what is achieved by his group’s new technique “MINFLUX”.

   Hell described the Achilles heel of the previous super-resolution techniques – the sheer number of photons needed. In contrast MINFLUX operates by the absence of photons emitted. It tracks fluorescing molecules with a doughnut shaped illuminating beam where fluorescence is suppressed in the centre, and uses the known mathematical description of how that fluorescence changes from the centre of the hole in the beam to pinpoint the molecule from what photons have been emitted. In an ideal world tracking the molecule with it dead centre of the beam would involve no fluorescence at all. This not only liberates the achieved resolution from a performance limited by the number of photons involved but means that images can be collected much faster – something biologists love. He showed a movie of a protein moving around in an e coli cell where the technique tracked 8000 protein localizations a second.

   The Wheatstone Lectures are an annual event at King’s College London that attract lay public and academics alike. The excitement of one University College London student pursuing a Masters on super-resolution techniques was infectious as he waited to hear the man who had won a Nobel Prize for work in this field describe the state of the art. The lectures commemorate the life and work of one of the college’s alumni Charles Wheatstone (1802-1875), a scientist and prolific inventor whose legacy includes the symphonium, the stereoscope and work on establishing the telegraph system and the Wheatstone Bridge.

   

   Professor Stefan Hell – Delivering the Wheatstone Lecture 2020

    

   Photo credit: King’s College London Department of Physics

   Words: Dr Anna Demming

    

    

    

    

    

4. Nader Engheta – 2019 OSA Annual Lecture – Imperial College London

   December 2, 2019 8:57 am Leave a Comment

   Imperial College Optics Society is proud to announce that the 2019 OSA Annual Lecture will be given by Prof. Nader Engheta on Metaphotonics. 

   The event, free of charge, will take place in the South Kensington Campus of Imperial College, Huxley Building, in Lecture Theatre 308, on Friday 13th December 16:00-17:00, and will be followed by drinks and snacks in the Level 8 common room of the Blackett Laboratory, where attendees will have a chance to discuss with Prof. Engheta and other researchers present.

   Abstract:

   Materials are often used to manipulate waves. Metamaterials have provided far-reaching possibilities in achieving “extremes” in such wave-matter interaction. Various exciting functionalities have been achieved in exploiting metamaterials and metasurfaces in nanophotonics and nano-optics.

   We have been exploring how extreme metamaterials can give us new platforms in metaphotonics for exploiting waves to do certain useful functions for us. Several scenarios are being investigated in my group. As one scenario, we have been developing metastructure platforms that can perform analog computation such as solving integral and differential equations and inverting matrices with waves as waves interact with them. Such “metamaterial machines” can function as wave-based analog computing machines, suitable for micro- and nanoscale integration. Another scenario deals with 4-dimensional metamaterials, in which temporal variation of material parameters is added to the tools of spatial inhomogeneities for manipulating light-matter interaction. The third category for metaphotonics is the concept of near-zero-index structures and associated photonic doping that exhibit unique features in light-matter interaction, opening doors to exciting new wave-based and quantum optical features.

   In this talk, I will present some of our ongoing work on extreme material platforms for metaphotonics, and will forecast possible future research directions in these paradigms.

   Ticket are available here –

   Biography:

   Nader Engheta is the H. Nedwill Ramsey Professor at the University of Pennsylvania in Philadelphia, with affiliations in the Departments of Electrical and Systems Engineering, Bioengineering, Materials Science and Engineering, and Physics and Astronomy. He received his BS degree from the University of Tehran, and his MS and Ph.D. degrees from Caltech.

   He has received several awards for his research including the Ellis Island Medal of Honor, the Pioneer Award in Nanotechnology, the Gold Medal from SPIE, the Balthasar van der Pol Gold Medal from the International Union of Radio Science (URSI), the William Streifer Scientific Achievement Award, induction to the Canadian Academy of Engineering as an International Fellow, the Fellow of US National Academy of Inventors (NAI), the IEEE Electromagnetics Award, the IEEE Antennas and Propagation Society Distinguished Achievement Award, the Beacon of Photonics Industry Award, the Vannevar Bush Faculty Fellowship Award from US Department of Defense, the Wheatstone Lecture in King’s College London, the Inaugural SINA Award in Engineering, 2006 Scientific American Magazine 50 Leaders in Science and Technology, the Guggenheim Fellowship, and the IEEE Third Millennium Medal.

   He is a Fellow of seven international scientific and technical organizations, i.e., IEEE, OSA, APS, MRS, SPIE, URSI, and AAAS. He has received the honorary doctoral degrees from the Aalto University in Finland in 2016, the University of Stuttgart, Germany in 2016, and Ukraine’s National Technical University Kharkov Polytechnic Institute in 2017.

   His current research activities span a broad range of areas including photonics, metamaterials, electrodynamics, nano-optics, graphene photonics, imaging and sensing inspired by eyes of animal species, microwave and optical antennas, and physics and engineering of fields and waves.

   tickets: https://www.eventbrite.com/e/prof-nader-engheta-metaphotonics-osa-annual-lecture-tickets-83770069533

   This event is organised by Imperial College Optics Society, a diverse group of graduate students working in optics who volunteer in the organisation of events such as lectures, seminars and other activities aimed at professional development and outreach in optics and related sciences, sponsored by OSA and SPIE. The Chapter welcomes students from all backgrounds with an interest in the optical sciences. Any further info may be found at: https://www.imperial.ac.uk/photonics/about-us/optical-society/

    

    

5. Quantum light at the nanoscale

   November 20, 2019 4:52 pm Leave a Comment

   Optical realisation of a quantum computer, secure quantum communications and imaging requires fast and reliable generation of single photons and their quantum superpositions. Future quantum optical sources should be small as they will need to be integrated into future photonics devices so that they fit ‘on-chip’.

   When an intense light impinges onto nonlinear material, high energy photons can split into two. This interaction divides their energy, leaving a pair of lower energy photons which are entangled. The first demonstration of a reconfigurable nanoscale light source of entangled two-photon states was realised by the multinational team involving the Photonics & Nanotechnology Group at the Physics Department at King’s College London (King’s).

   Nano-antennas are nanometric material structures that strongly interact with light.  Optical nano-antennas have already shown a great ability to manipulate photons efficiently, but their potential for production of multi-photon quantum states remained unexplored.

   In the framework of a multinational collaboration involving researchers in the UK, Australia, France, Italy and China, Dr Giuseppe Marino, a PhD student from the Photonics & Nanotechnology Group at King’s and current postdoctoral fellow at  Université de Paris, has experimentally demonstrated, the nanoscale generation of two-photon quantum states enhanced by the nanoscale semiconductor antenna. It is also easy to achieve the desired spectral response by changing the nano-antenna shape and geometry.

   When excited by a laser, the nano-antenna generates pairs of photons at a much higher rate than usual methods. The research ‘Spontaneous photon-pair generation from a dielectric nanoantenna is published in Optica.

   These experiments now pave the way to the development of nanoscale structures to generate multi-photon quantum states.  Future applications include secure telecommunications and quantum imaging.

   “Scalable and integratable nanoscale quantum optical sources are a must if the optical quantum technologies will grow from the lab to real-world applications,” says Professor Zayats, a co-author of the paper, “these results show that indeed such miniaturised optical sources can be engineered not only without compromising the performance but actually with better performance than their traditional bulky counterparts”.

   Link to the paper: (doi.org/10.1364/OPTICA.6.001416)

    

6. Seminar – 14 October – Prof. Tuan Vo-Din

   October 8, 2019 3:47 pm Leave a Comment

   Next Monday, 14 October, Dr Manuel Müller will be hosting Prof. Tuan Vo-Dinh (Duke University) who will be delivering a seminar in G8, New Hunt’s House, Guy’s Campus,  King’s College London, SE1 9RT @ 16.30.

    

   Prof. Tuan Vo-Din is in the UK to as the recipient of the 2019 Royal Society of Chemistry Sir George Stokes Medal

   https://www.rsc.org/ScienceAndTechnology/Awards/SirGeorgeStokesAward/2019-Winner.asp

    

   His abstract is below.

    

   Plasmonic Nanosensors and Nanoprobes:   Harnessing the Power of Photonics for Medical Diagnostics and Therapy

    

   This lecture provides an overview of recent developments in our laboratory for several plasmonic nanoplatforms and biosensing technologies that allow biomedical diagnostics from the gene level to single-cell, and whole body systems. Plasmonics refers to the research area of enhanced electromagnetic properties of metallic nanostructures that produce ultrasensitive and selective detection technologies. The technology involves interactions of laser radiation with metallic nanoparticles, inducing very strong enhancement of the electromagnetic field on the surface of the nanoparticles. These processes, often called ‘plasmonic enhancements’, produce the surfaceenhanced Raman scattering (SERS) effect that could enhance the Raman signal of molecules on these nanoparticles more than a million fold.  A SERS-based nanoprobe technology, referred to as ‘Molecular Sentinel’ nanoprobes, has been developed to detect early biomarkers (mRNA, miRNA) of cancer (e.g., BRCA1, ERB2 cancer genes). A unique nanoplatform referred to as gold nanostars, offers plasmon properties that efficiently transduce photon energy into heat for photothermal therapy. Nanostars, with their small core size and multiple long thin branches, exhibit intense two-photon luminescence, and high absorption cross sections that are tunable in the near infrared region with relatively low scattering effect, rendering them efficient efficient photothermal agents in cancer therapy. A theranostics nanoplatform construct was created, allowing SERS imaging and photodynamic therapy. SERSbased plasmonic nanoprobes and nanochip systems have also been developed for use as diagnostic systems for point-of-care personalized nanomedicine and global health applications.  We have recently developed a novel two-pronged modality by merging gold nanostarsenhanced photothermal treatment with checkpoint immunotherapy into a Synergistic Immuno Photothermal Nanotherapy (SYMPHONY), which has the potential to eradicate both primary tumours and ‘untreated’ distant metastatic foci. Delayed rechallenge with repeated bladder and brain cancer cells injections in cured mice did not lead to new tumour formation after several months of observation, indicating that SYMPHONY induced effective long-lasting immunity like an anti-cancer ‘vaccine’ effect against cancer in  murine models.

7. King’s hosts the 5th annual London Plasmonics Forum

   June 20, 2019 5:06 pm Leave a Comment

   The Fifth London Plasmonics Forum was held at Kings College London on 14 June in the Anatomy Museum at the Strand Campus, this time as part of the London Tech Week.

   The event has been running since 2015, and it typically attracts approximately 100 participants from London, UK, Europe and beyond. It aims to engage and connect researchers and industry who work in the ever-expanding field of Plasmonics.

   Dr Charles Footer from QinetiQ gave the keynote talk; explaining the way that materials and metamaterials are used in industry. Following on from the keynote, there were several talks from early career researchers , Dr Andres Neira from Seagate Technology gave a talk on progress in heat-assisted magnetic recording, and Dr Dominic Gallaher from Photon Design talked about the development of new simulation tools for nanophotonics.

   

   From L-R – Rachel Won (Nature Photonics), Ediz Herkert (University of Stuttgart), Anatoly Zayats (RPLAS PI) & David Pile (Nature Photonics)

   Over lunchtime there was a lab tour of the nanophotonics lab running alongside the annual poster competition. As usual, the standard of the competition was very high; Rachel Won and David Pile from Nature Photonics announced the winner as Ediz Herkert from the University of Stuttgart for his poster entitled ‘Computing the influence of disorder in plasmonic metasurfaces’.

   Professor Anatoly Zayats, Co-Director of the LCN and PI of the EPSRC programme grant Reactive Plasmonics said “This is the 5th year we’ve run the London Plasmonics Forum, and it is amazing to see how plasmonic research changed over this relatively short period. It has diversified in so many different areas which we could not even think about 5 years ago. It continues to be a very active and imaginative area of photonics, chemistry and biological research and we always have very lively discussions at the Forum with our colleagues from all around the world.”

   The event continues to build on its excellent reputation for researchers and industry to come together to discuss, exchange ideas and disseminate cutting edge research and plans for the 6th London Plasmonics Forum are already in place for 2020.

8. Photonic skyrmions discovered

   April 25, 2019 7:58 pm Leave a Comment

   Skyrmions, ‘hedgehogs’ of electron spins, are well known in magnetic materials and were long considered for applications in spintronics and high-density data storage. However, electromagnetic waves also carry spin and orbital angular momenta. In a recent paper, the team of researchers from Shenzhen University in China and King’s College London and London Centre for Nanotechnology in the UK have discovered the skyrmion structures made of photon spins.

   The team has shown a direct analogy between photonic spin structures observed in optical field with orbital angular momentum and skyrmions in magnetic materials. Interestingly, a free-space focused vector beam produces photonic skyrmion-like feature corresponding to a Bloch-type skyrmion in magnetic materials, while a waveguided beam leads to a Neel-type skyrmion. There are no skyrmion-like structures for unfocused propagating vector beams. This phenomenon is caused by strong spin-orbit coupling effects which result in an exchange of spin and orbital angular momenta and provide topological protection.

   Even more interestingly and importantly for applications, the researchers demonstrated that the photonic spin structure of a focused vortex beam varies on the deep-subwavelength scales, down to 10 nm distances, greatly exceeding the diffraction limit. Diffraction always limits the size of spatial intensity distributions, however the direction of the field, defining its polarisation and spin, is not affected by diffraction and can be observed at much finer, deep-subwavelength scales. The application of the observed photonic skyrmions with such nanometric features may range from high-resolution imaging and precision metrology to quantum technologies and data storage where the analysis of the spin structure of the beam, not its intensity, can be applied to achieve deep-subwavelength optical field patterns.

   In order to achieve this experimentally, the team constructed and validated a unique scanning probe experimental set-up capable of achieving the above-mentioned resolution in measuring the spin structure of the optical beams.

   Professor Anatoly Zayats of King’s College London said: “electrons and photons are very different animals with different properties defining their behaviour, such as spin and statistics. However, in the specially designed environments photon exhibit very similar behaviour to electrons, such as, for example, topologically protected states (something unheard for photons until very recently). The demonstrated photonic skyrmions is another example of how well-known electron phenomena can be transposed into the photonic domain, where they can be used for developing new applications.”

   The article “Deep-subwavelength features of photonic skyrmions in a confined electromagnetic field with orbital angular momentum” is published in Nature Physics,

   DOI: 10.1038/s41567-019-0487-7

9. Womxn in Physics London 2019 Conference

   March 28, 2019 6:56 pm Leave a Comment

   The WiP London 2019 Conference was inspired by the Conference for Undergraduate Women in Physics (CUWIP UK) organised by the University of Oxford. WiP London was first organised by a second year KCL undergraduate, Miho Wakai, having attended CUWIP UK last year. She took the initiative to carry forth this conference and bring it here to King’s College London. 

   Starting out as just an evening of talks from specialists in different areas of physics, this conference has now become a day long event, with talks from speakers on their research or work and any challenges they may have faced during the process of their careers. There was also a panel structured on the ‘Future of Physics’, with panelists ranging across post graduates and doctorates. To conclude the conference, there was a networking reception where attendees had the opportunity to meet and speak to panelists or speakers from the conference. 

   Dr Sasha Rakovich & Dr Amelle Zaïr from King’s College London will be at the event that will be held on 30th March 2019

   To register to click here

10. Optics Masterclass – Quantum Fluids of Light – Dr. Alejandro Soto Zamora

    February 19, 2019 11:15 am Leave a Comment

     

     

     

     

     

    The next optics masterclass organised by Imperial College Optics Society (ICOS) will be given by Dr. Alejandro Soto Zamora from UCL on “Quantum Fluids of Light” on Tuesday 26th February at 2pm in Blackett 539. Please see the details below. As always, the session is aimed at graduate students and younger researchers although anyone is welcome to attend (no need to book). Drinks and snacks provided. 

     

     

     

     

     

    Abstract:

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    ‘Quantum fluids of light’

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    Driven-dissipative systems in two dimensions can differ substantially from their equilibrium counterparts. Particularly, quantum fluids of light, such as exciton-polaritons in microcavities, constitute paradigmatic cases of non-equilibirum physics. These quantum systems, which appear as a consequence of the hybridization between light and excitons, are not isolated due to the existence of i) an external pumping laser that maintains a finite density of polaritons ii) a non-zero dissipation due to the leaking of cavity photons through the mirrors. The subtle interplay between the external drive and the cavity losses may drive the system to exotic and genuinely non-equilibrium phases. Moreover, demonstrations of polariton lattices in semiconductor microcavities, in combination with their extraordinary non-linear properties, place these quantum-fluids of light as one of the most promising candidates to achieve quantum simulation in compact on-chip scalable platforms. In this lecture I will give an introduction to the physics of quantum fluids of light and the different techniques in order to study the static and dynamical properties of such non-equilibrium systems. I will review the state of the art of this particular field and will mention different open questions and future research topics concerning microcavity polaritons and non-equilibrium systems. 

     

    You can find out more about ICOS at our web page:

     

    http://www.imperial.ac.uk/photonics/about-us/optical-society/