Scan the news below -- then see more photos in the photo gallery.
A great week!
Representatives from among the 183 companies participating in the SPIE Optics + Photonics 2015 exhibition heard good news from many fronts at the exhibitor breakfast Thursday morning in the sunny Sails Pavilion (above).
Registration for this year's meeting was up over 3% from last year, at 4,446, reflecting good traffic and reports of many high-quality leads in the exhibition hall, said SPIE Exhibitions Manager Roberta Hart. Attendance was strong in the conference rooms as well for the event's more than 3,300 talks.
SPIE Industry and Market Analyst Steve Anderson presented the latest updates in the ongoing photonics market analysis by the society, with results including growth in revenues, jobs, and companies in the world's core photonics industry.
SPIE Optics + Photonics 2016 will run 28 August through 1 September in the San Diego Convention Center -- see you next year!
Manipulating organic materials and devices
Thursday sessions on photo-mechanics, light-triggered, and light-actuated materials in the conference on Light Manipulating Organic Materials and Devices covered a variety of materials and applications.
Julia Kornfield of California Institute of Technology (9564-16) showed electro-optic liquid crystal networks. The material is opaque, but when an electric field is applied, the material becomes transparent. Kornfield uses an "unhappy" molecule: the polymer backbone likes to curl together into a small ball but the liquid crystals like to align with each other. This tension in the material makes it ideal for electro-optic materials.
Zuliekha Kurji of Washington State University (9564-17) discussed work with liquid crystal networks and two materials. The materials start with a polymer backbone to which liquid crystals are attached. For one material, the dyes are also attached to the backbone. The materials are cross-linked and various material properties are measured. The material with the dye reacts by changing length when exposed to light.
Zouheir Sekkat of Moroccan Foundation for Advanced Science, Innovation and Research (9564-18) showed how radially polarized light can manipulate azobenzene-doped polymers to move material away from areas of high light intensity. The material rises out of the plane of the material, creating hills and valleys. For thin materials, the surface topology can be inverted by decreasing the optical gradient force through index-matching fluid.
Yin-Lin Cheng of National Taiwan University of Science and Technology (9564-19) presented a new way to 3D-print tissue scaffolds using biocompatible polymers. Instead of extruding the polymer, Cheng proposed using a liquid crystal display harvested from a cell phone to create a mask. This mask allows visible light to travel to a tank of the biocompatible polymer, "printing" the scaffold one layer at a time.
Irakli Chaganava of Institute of Cybernetics and Georgian Technical University (9564-20) demonstrated how transmission of light can be controlled in polarization-sensitive materials. With "usual" materials, transmission of light increases the longer the material is exposed to light. With "unusual" materials, transmission at first increases, but then decreases! Further, the transmitted wavelengths can be controlled by changing the polarization of the light.
Happy in the exhibition hall
Proximity to the technical sessions continued to be a popular aspect for exhibitors, as the optics and photonics show continued into the second day.
"We have had a lot of good leads and customers visiting the booth. The exhibition is a nice size and close to the conference, so there is time to talk, which is great. We really like the location," said Brock Koren, Business Development Manager at Zygo Corporation.
See more photos from the exhibition in the event photo gallery.
Probing for exoplanets
Sara Seager of MIT presented an invited talk (9605-31) in the conference on Techniques and Instrumentation for Detection of Exoplanets, to kick off a Wednesday afternoon session devoted to the Exo-S mission. The mission consists of a 34-meter starshade and a 2.4-meter telescope flying in formation. Starshades enable detection and characterization of faint exoplanets.
One of two "probe-scale" proposals to study exoplanets with a cost target of under $1 billion, the Exo-S concept would launch only the starshade spacecraft as an add-on to an existing space telescope mission. This concept was significantly under the probe-class cost target.
The telescope chosen was the Wide Field Infrared Survey Telescope/Astrophysics Focused Telescope Assets (WFIRST-AFTA), which will have been launched by the 2018 target date for the starshade mission, and "can be made starshade-ready," Seager said. An LED bank on the starshade will enable calibration of the spacecraft pair to plus or minus one meter, traveling through space 35,000 km apart. While the mission is not yet fully funded, testing is well underway, including subscale optical testing, she said.
Seager said that observing different stars and their exoplanets requires repositioning of the telescope, which cuts into observing time and also requires onboard fuel for propulsion. On the positive side, the design enables Exo-S to be a "real-time mission," Seager said, allowing scientists to respond to new discoveries.
Congratulations! SPIE award winners honored
2015 Directors' Award
2015 President's Award
SPIE Past President Eustace Dereniak, Professor Emeritus, University of Arizona College of Optical Sciences, was announced as winner of the society's 2015 President's Award and SPIE Fellow Jim Oschmann, Vice President and General Manager of the Civil Space and Technology business unit of Ball Aerospace, of the 2015 Directors' award at an annual awards banquet Wednesday night.
The awards were announced by SPIE President Toyohiko Yatagai (below, left) of Utsunomiya University and presented along with several others announced earlier, including the society's highest honor, the Gold Medal of the Society, to Nader Engheta (below, right) of the University of Pennsylvania.
Also receiving awards at the banquet were:
- Richard Juergens (Raytheon Missile Systems), A.E. Conrady Award
- Aristide Dogariu (University of Central Florida), G.G. Stokes Award
- Rajpal Sirohi (Tezpur Univerity), Chandra S. Vikram Award in Optical Metrology
- Virendra Mahajan (The Aerospace Corporation), SPIE Educator Award
- Alan Lee (LongWave Photonics LLC), Early Career Achievement Award, Industry Focus.
Read more in the SPIE press release.
Members of distinction
SPIE Senior Members were treated to breakfast in their honor Wednesday morning, and more than two dozen of this year's 171 new Senior Members were introduced. Senior Members are honored for their professional experience, their active involvement with the optics community and SPIE, or significant performance that sets them apart from their peers.
Industry leaders provided insights and advice in a well-attended discussion Wednesday morning on Women in the Optics and Photonics Workplace. Panelists were, from left, Sophia Hayes (University of Cyprus), Rosalie Clemens (ASE Optics), and Katerina Moloni (nPoint, Inc.). SPIE Marketing Analyst Adam Resnick, at the podium, provided results from the SPIE 2015 Optics and Photonics Global Salary Report, which included a special focus on what women in the field report about salary and other issues.
A speed networking social at Roy's Wednesday afternoon provided the opportunity for participants to make new contacts every three minutes. The popular event draws students as well as early-career and established professionals.
Exhibitors report good leads, great location
The three-day exhibition opened Tuesday morning with a flood crowd, and exhibitors reported a strong first day.
For some, opening day was so busy, there was no time for a break.
"The German company I rep is excited by the size of the U.S. market," said Harry Skolnik of LightTrans GmbH. "This is the first time this software product has been shown at Optics + Photonics, and I've made good, new contacts on the first day of the show."
Others reported good results through presenting at the conference and participating in the exhibition.
"Our product is a whole new way of making x-ray that was discovered in 2008 and is being brought to market now in 2015," said Carlos Camara, Chief Scientist at Tribogenics, who was exhibiting for the first time with SPIE. "We presented at the conference, and now attendees can come put their hands on the device at our display. The positive response at Optics + Photonics is the validation by the technology community that our new x-ray source works!"
Another first-time exhibitor, Derek Nowak, Staff Scientist for Molecular Vista, had a similar comment.
"Our co-founder spoke at the conference on Sunday. We are exhibiting to bring the new version of our product to market," Nowak said. "We have added a new optical twist to our previously existing product and are here at Optics + Photonics to educate our current and potential customers how this new version of the product will better solve their problems."
See more photos from the exhibition in the event photo gallery.
A Job Fair sponsored by the SPIE Career Center (above left) brought together job-seekers with employers looking to fill positions. Companies with representatives on-site to talk with interested ptotential employees included Andover Corporation, Apple, Applied Materials, General Atomics Aeronautical, GMTO, II-VI Optical Systems, Johns Hopkins University Applied Physics Laboratory, L3. Microsoft. Moxtek, and Trioptics.
Above right, a viewer looks over the contestants for the People's Choice Award in the SPIE International Year of Light Photo Contest. Voting is open until this Saturday. The winning photograph will appear on the cover of the October SPIE Professional magazine.
Organic electrodes for studying the brain
In the Organic Photonics and Electronics plenary session Tuesday morning, George Malliaras, Ecole Nationale Supérieure des Mines de Saint-Étienne, gave a glimpse into future directions of research and diagnosis of brain function in a talk on his group's work with organic electrodes. The work aims to improve the methodology used to monitor and record epileptic episodes.
Conventional methods rely on traditional metal electrodes which suffer from sensitivity to noise. The organic electrodes developed by Malliaras are based on organic electrochemical transistors (OECT), with conductance proportional to the volume of the transistor, not the area. Additionally the OECT electrode probes demonstrate higher transconductance, meaning that higher currents are generated in the OECT whenever an action potential is detected, allowing for a higher signal-to-noise ratio.
In one experiment, metal electrodes were placed on the surface of the brain and deeper inside the brain tissue. Readings were compared to an OECT-based electrode placed on the surface of the same brain. The organic-based electrode was able to detect the action potentials that the metal electrode placed inside the brain tissue detected, while the complementary surface-placed metal electrode was not.
Malliaras also noted that by using OECT more advanced brain monitoring can be realized. By using different thicknesses, neuron activity of different firing rates can be detected.
'Amazing' perovskites and solar cells
In his plenary talk, Yang Yang of the University of California, Los Angeles, summarized recent progress in working with light-harvesting hybrid perovskite materials and reported on new results from UCLA (e.g. interface engineering, perovskite-based photodetectors and tandem solar cells.
"Perovskites are a really amazing material, from a purely scientific point of view," Yang said in an interview during Optics + Photonics with SPIE.
High absorption, good transport properties, and low-cost processing make them attractive for solar energy, he said, compared to a lot of "high-end" solar cells that require special equipment. He predicted that if perovskites can be shown to have long-term stability, they would reduce the cost of solar energy "comparable to or even lower than fossil fuels."
Yang said the most efficient are "tandem" solar cells, utilizing two or more materials in layers, which he compared to a double-decker bus carrying more passengers.
"It's hard to find one single material to pick up all the photons," he said. Unfortunately that technology is still cost-prohibitive and used mostly for space applications.
In the opening talk of the Organic Photonics and Electronics plenary session, Chihaya Adachi of Kyushu University reviewed material design, synthesis, photophysics, and future prospects in a talk on highly efficient thermally activated delayed fluorescence (TADF) molecules and their OLED performance.
Organics for wearables and implantables
In his plenary talk, Takao Someya of the University of Tokyo described emerging applications using ultraflexible and stretchable electronic systems in the fields of biomedical electronics, reporting on recent progress of ultraflexible organic thin-film devices that are manufactured on ultrathin plastic film with the thickness of 1 μm.
Flexible and stretchable devices are expected to open new possibilities in fields of wearable and implantable electronics. Conformability, ruggedness, light weight, biocompatibility, and large-area are all important to create new electronic applications that can be directly mounted on the surface of human skins and/or even inside the body. Ultraflexible organic thin-film devices such as organic thin-film transistors (OTFTs), organic photovoltaic cells (OPVs), and OLEDs, have attracted much recent attention.
Making the most of the International Year of Light: at the Fellows luncheon
Make the most of the International Year of Light and Light-based Technologies (IYL2015), urged SPIE CEO Eugene Arthurs in a talk at the Fellows luncheon Tuesday afternoon.
The United Nations-decreed celebration has been impressively effective in raising awareness about photonics -- even bringing the word into the vocabularies of U.S. Vice President Joe Biden and other policy makers.
Through visits with policy makers, outreach to science teachers, hands-on lessons and demonstrations for students from the earliest grades through adults, and projects to bring solar-powered LEDs to areas off the electrical grid, much has been done this year to raise awareness and share the benefits of light-based applications.
But those gains should only serve to encourage more activity, Arthurs said.
While light-based technologies have done much to advance and enhance human existence, there is still much that needs to be done, to end poverty and make good on the promise of shared prosperity through the world, he said.
Arthurs was among many speakers throughout the week who encouraged a continuation of the efforts toward awareness begun this year. Based on the energy and vision of supporters, the plans for the IYL2015 "closing" ceremonies to be held in Mérida, Mexico, in February will surely involve a shift in focus from the end of the observance, to the beginning of what is next.
SPIE President Toyohiko Yatagai introduced 9 of the 58 new Fellows of the Society named in 2015, and led a moment of silence for those who have passed away during the last year. New Fellows recognized at SPIE Optics + Photonics were:
- Javier Alda (Universidad Complutense de Madrid)
- Jonathan Arenberg (Northrup Grumman Aerospace Systems)
- Ni-bin Chang (University of Central Florida)
- Judith Donnelly (Three Rivers Community College, retired)
- Ronald Pirich (Northrop Grumman Aerospace Systems, retired)
- Federico Rosei (Université de Québec)
- Ravindra Sinha (Delhi Technological University)
- Yasuo Tomita (University of Electro-Communications)
- Zhanshan Wang (Tongji University).
See more photos from the Fellows luncheon in the event photo gallery.
Focus on texture: Signal, Image, and Data Processing
Texture analysis is important in image compression and image analysis. Although texture similarity can easily be detected with the human eye, image processing techniques struggle with distinguishing between similar and dissimilar textures. This is due to the unsuitability of conventional imaging metrics for texture discrimination. Two major imaging metrics incorrectly identify dissimilar and similar structures.
In the Tuesday afternoon Signal, Image, and Data Processing plenary talk, Thrasyvoulos Pappas of Northwestern University discussed new metrics he developed for texture discrimination, inspired by the work of Wong in which an image is classified according to statistical properties and not deterministic properties. The original implementation of texture identification used by Wong relied on over 600 parameters. With redesign, Pappas was able to reduce the number of metrics for texture to around 60 to 65 parameters.
One interesting result showed that for proper texture reconstruction the image does not have to look identical to the original and that textures could be reconstructed so that the outcome subjectively appears identical to the reader but is objectively different.
Pappas' group employed their metrics for analyzing blood vessels. Through texture comparison and clustering, they were able to discriminate diseased from health blood vessels.
Democratization of next-generation imaging, sensing, and diagnostic tools
In the Optical Engineering plenary session Tuesday afternoon, Aydogan Ozcan of the University of California, Los Angeles, and California Nanosystems Institute overviewed the burgeoning field of mobile health technologies, offering a compelling argument for why mobile health represents the new frontier of health care.
Most of the approximately 7 billion mobile phones in the world contain high-pixel-count CMOS cameras which can be leveraged, with the power of computational imaging, to perform on-site diagnostic testing, Ozcan said.
One device introduced uses lensless imagining and phase retrieval algorithms to image micro-organisms via mobile. The computational power needed to reconstruct the hologram generated from imaging with LED sources is done on remote servers, thus offloading the computational load on the cellphone hardware.
However, images obtained using lensless holography in this manner suffer from the pixel resolution limitations. To overcome this, another holographic microscope implementation was proposed. In this design, a stage containing the sample is shifted left and right while a video of the image is recorded. These shifted sample frames are used to further sample the frequency domain thus providing higher resolution during reconstruction and allowing for imaging of features beyond the spatial resolution limit imposed by the pixel sizes.
Ozcan also showed how his mobile based microscopes were able to record the trajectory of sperm. From the data, about 10% of sperm were shown to move in helical trajectories. Why such a trajectory is taken is unknown, however, Ozcan reported that such a movement path has never before been seen or reported with other technologies.
Designing the next-generation of wearable displays
In his plenary talk, Bernard Kress of Google described changes in the optical engineering "toolbox" to solve requirements ranging from smart glasses, to augmented reality, to virtual reality.
Kress noted that since the first versions of smart glassess were introduced to the public three years ago, many major consumer electronics companies have unveiled multiple versions of eyewear-based headsets. Today, the question for optical designers in particular is not, "will the market happen?" but rather, "which optical technologies will be best fitted for the various declinations of the existing wearable display market."
For example, augmented reality requires development of see-through monocular or binocular displays.
In the domain of gaze-tracking optics, the engineering foundation includes combiner optics, exit pupil expanders (EPE), imaging optics and display.
Field of view, size of display, and image resolution are among the critical factors affecting perceived quality and usability in wearable systems.
Changes in the funding landscape
The landscape for funding new ventures is changing, and a panel discussion on the topic Tuesday afternoon was one of several focused sessions on industry topics held during the week. Panelists were, from left, Allen Oppenheimer (A.M. Oppenheimer, Inc.), Mark Wippich (LightWave Advisors), and Michael Larson (Tissue Fusion LLC). At the podium is moderator Brandon Conover of Practical Scientific Solutions, Inc.
Chapters in the spotlight
Student chapter members shared their work in a mixer on the exhibition floor showcasing the many outreach and research activities undertaken by SPIE student members across the globe. SPIE has nearly 300 Student Chapters and Clubs worldwide.
Election results: new officers, directors chosen
SPIE Fellow and Journal of Medical Imaging Editor-in-Chief Maryellen Giger, University of Chicago, has been elected to serve as the society's 2016 Vice President, announced SPIE President Toyohiko Yatagai at the Annual General Meeting of the Society on Tuesday evening. With her election, Giger joins the SPIE presidential chain and will serve as President-Elect in 2017 and President in 2018.
Newly elected Society Directors, who will serve three-year terms for 2016-2018, were also announced:
- David L. Andrews, University of East Anglia
- Jennifer Barton, University of Arizona
- James Fujimoto, Massachusetts Institute of Technology
- Joseph Howard, NASA.
Other officers elected are Robert Lieberman, Lumoptix LLC, who will serve as the 2016 President of the Society; Glenn Boreman, University of North Carolina at Charlotte, and Plasmonics, Inc., who will serve as President-Elect; and Gary Spiegel, retired from Newport Corp., who will serve as Secretary/Treasurer. (From left above are SPIE Immediate Past President Philip Stahl of NASA, Yatagai, Lieberman, Boreman, and Spiegel.)
Read more in the SPIE press release.
A characteristically gorgeous San Diego sunset and delicious rooftop supper provided the backdrop for the member reception Tuesday evening on the terrace of the Marriott Hotel. The reunion of new and longtime colleagues included a gracious salute from SPIE leadership to staff commemorating the 60th anniversary of the society.
See more photos in the event photo gallery.
High profile for sustainable energy
The growing significance of renewable energy sources to the US energy sector was reflected by the high profile given to this subject at the packed Sustainable Energy plenary session featuring four specialist speakers.
Wyatt Metzger (U.S. National Renewable Energy Lab) told the conference that the latest research into cadmium telluride solar cells is targeting 24% efficiency, "which is driving the cost down to less than $0.40/W, and could displace the dominant silicon market share, and reach grid parity," he said.
"By maximizing photocurrent, CdTe cell efficiency has recently reached 21.5% and surpassed the performance of multicrystalline silicon. There is still headroom to increase performance further by improving hole density, lifetime, and thereby photovoltage."
Metzger presented a review of the commonest types of PV materials in use and analyzed their pros and cons. Silicon is probably the best-known of these media, with most coming from China today, he said; while II-V materials such as gallium arsenide offer relatively ultrahigh efficiency but also high cost, and II-VI films such as CdTe are now challenging silicon.
Timothy Schmidt (University of New South Wales) discussed the processes and energy benefits of the photochemical upconversion (PUC) of light, in which lower energy photons are converted to higher, for renewable energy. PUC has been applied to solar cells, increasing the external quantum efficiency of the devices in the region below the bandgap of the device, he said.
Becca Jones-Albertus (U.S. Department of Energy Solar Energy Technologies Office) oversees $200 million in funding which is intended to reduce photovoltaic material and process costs, increase module efficiency, and improve module reliability, towards and beyond the goals of the SunShot initiative. The initiative was launched in 2011 to make subsidy-free solar electricity cost competitive with conventional energy sources by 2020.
Research in reliability plays a major role in realizing these energy efficiency goals, she said. Improving photovoltaic module lifetime and reducing degradation rates increase the lifetime energy output. Increasing confidence in photovoltaic system performance prediction can lower perceived investment risk and thus the cost of capital.
Dengwei Jing presented on "Solar hydrogen: harvesting light and heat from the Sun," on behalf of Liejin Guo (Xi'an Jiaotong University).
Jing's research group has focused on renewable energy, especially solar hydrogen, for about 20 years. He presented the latest progress in hydrogen production using light and heat, starting with"cheap" photoelectrochemical and photocatalytic water splitting (so-called artificial photosynthesis).
He then described his group's achievements on "thermal-driven solar hydrogen" -- the use of concentrated solar light and its application to biomass/coal gasification in supercritical water for large-scale and low-cost hydrogen production.
For more, see the optics.org article.
Extreme imaging and beyond
In the first of three Nanoscience and Engineering plenary talks, Keisuke Goda (University of Tokyo) spoke on the current limits of the speed of imaging. Some fields of science are asking for ultrafast, but some also for ultraslow imaging, since both can exceed the human time scale.
The two fastest imaging techniques currently available are STEAM (serial time encoded amplified microscopy/imaging) and STAMP (sequentially timed all-optical mapping photography). The principal idea behind STEAM is to create an "optical shutter", instead of the mechanical or electrical that are currently in use.
The unique feature of STEAM is spectrally structured illumination, obtained by the serialization and optical amplification of a broadband pulse in the temporal domain, after which it is detected by a high-speed camera. STEAM has been applied in flow cytometry, looking for rare breast cancer cells in blood, and for lipid detection in algal cells for the production of biofuel.
STAMP is the fastest burst-mode photography currently available, with up to 5 trillion frames per second. It is based on a spatial and temporal dispersion of a light pulse and results in a sequence of images each recorded in a different color. The time frame is therefore limited to how far apart the mechanism can separate the wavelengths of one pulse. STAMP has been applied in the imaging of laser ablation, and phonon imaging.
The other side of human limitations in imaging is slower than a person's lifetime. The key example is the field of earthquakes and the imaging of the very slow friction between tectonic plates. Since regular friction laws are not valid in conditions of extremely high pressure and slow sliding speed, making modeling and simulations nearly impossible.
Small and smaller: nanoaperture tweezers
Utilizing conventional optical tweezers requires very high intensities for the length scale of individual proteins (1 to 50 nm), causing severe damage to the sample. In his Nanoscience/Engineering plenary talk, Reuven Gordon (University of Victoria) presented a modified optical tweezer which utilizes nanoholes to trap very small objects with less than 1 mW of light power.
A traditional optical tweezer holds ~100 nm objects at the beam's waist for a period of time so that researchers may observe the sample's properties. Gordon's nanoholes hold 1-50 nm objects in the center of an aperture; while an object is trapped, the transmission through the aperture increases significantly. By increasing the power to 1 mW, Gordon's modified optical tweezers can hold samples basically indefinitely.
To trap even smaller objects, a double nanohole (DNH) structure is etched in gold. The DNH consists of two barely touching holes, which creates two sharp peaks, focusing the electric field and increasing the optical tweezer's hold on small samples.
Once a protein, DNA strand, antibody, or virus is trapped in either the nanohole or DNH structure, the transmission increases, and interpreting the noise in transmission leads to information about the protein. Gordon proposes using this modified optical tweezers to study how medicines impact one single protein.
Another application of the DNH structure is determining how certain proteins delay the unzipping and binding of DNA. Some proteins delay DNA replication time, which may lead to advanced cancer treatment drugs that slow the spread of cancer.
Resonant nanostructures and metafilms
The third plenary talk, by Mark Brongersma of the Geballe Lab for Advanced Materials, covered the use of individual, resonant nanostructures and dense arrays thereof (metafilms) in a variety of optoelectronic devices. Brongersma illustrated how the performance of these devices can be improved by engineering the constituent nanostructure, size, shape, and/or spacing.
Semiconductor nanostructures are at the heart of modern-day electronic devices and systems. Due to their high refractive index, they also provide a myriad of opportunities to manipulate light. When properly sized and shaped, they can support strong optical resonances that boost light-matter interaction over bulk materials and enable their use in controlling the flow of light at the nanoscale.
Women celebrate the International Year of Light
During the Women in Optics presentation and reception, Sona Hosseini of University of California, Davis; Laura Tobin of University College Dublin; and Anne-Sophie Poulin-Girard of Université Laval (seated, from left above, with moderator Halina Rubinsztein-Dunlop of the University of Queensland at the podium) focused on women's presence in the International Year of Light (IYL) optics outreach. Each young career professional highlighted a different area of the world and its IYL outreach efforts.
Hosseini first noted women face many levels of challenges. Certain areas of the world do not allow women to pursue any sort of education; meanwhile, educated women face hiring discrimination in other areas of the world. However a large number of IYL outreach events are primarily organized by women.
Wales, for example, had an event featuring six speakers, and five of the speakers where women. Mexico is particularly empowering to women, as many women are participating in IYL activities.
Many outreach events aim to highlight how optics improve the quality of life for citizens. In Iran, solar panel "umbrellas" were installed in new parks to provide shade while also creating a sustainable and clean source of energy. A "Lighting up Africa" workshop in Tunisia featured low-cost optics experiments that participants from 12 different countries could demonstrate in their home countries to teach students about optics.
Many outreach activities combine light and art. In Spain, 16- to 18-year-olds attended a workshop to create light-based art, which was on display in a public museum. In addition to public art, professors in Spain developed a series of posters featuring 12 women researchers who contributed fundamental discoveries to optics and photonics.
Luncheon with the experts
Monday afternoon's "lunch with the experts" afforded students a chance to expand their networks over a casual meal. Newport Research Excellence Travel Awards and SPIE Scholarships were presented during the event -- see the gallery for photos of the winners.
Optical Trapping tribute to a pioneer
Attendees at the conference on Optical Trapping and Optical Micromanipulation (above) heard a recorded message from Arthur Ashkin, who is credited with pioneering the field of optical tweezers while working at Bell Labs in the 1960s. Dr. Ashkin, 92, said the field is still ripe with possibilities and should be an interesting area of research for a long time to come. In turn, conference attendees posed for a group photo and recorded a message to send back to Ashkin thanking him for his contributions in the field.
The conference is in its 12th year this year, and chaired by Kishan Dholakia (University of St. Andrews) and Gabriel Spalding (Illinois Wesleyan University).
Face-to-face at the poster session
The first of the week's two poster sessions provided ample opportunity to discuss new research face-to-face with the authors on Monday evening.
Welcome -- San Diego style
A San-Diego-style Optics + Photonics welcome reception Monday evening featured a view of sunset from the convention center terrace, looking out over the harbor -- and up to the stars, thanks to the telescopes of the San Diego Astronomy Club.
See more photos in the event photo gallery.
Opening night: the symposium-wide plenary session
A symposium-wide plenary session drew a large crowd to hear talks on the Rosetta mission and wave-sculpting at the nano scale.
Rosetta: landing Philae -- and what's next
U.S. Rosetta Project Manager Artur Chmielewski (Jet Propulsion Lab, NASA) opened the symposium-wide plenary session with a review of the Rosetta Mission, which last year set down the Philae lander on comet "67P" while more than 400 million kilometers from Earth.
Chmielewski also announced the decision made just a days before SPIE Optics + Photonics to conclude the photonics-heavy mission by landing the Rosetta orbiter itself on the comet, in 2016. (Read more in the optics.org article.)
The European and German Space Agencies built the Rosetta spacecraft, which transported the Philae lander to the comet, and the U.S. has donated various pieces of equipment to the project, Chmielewski explained.
Rosetta, he said, is about the size of the biggest SUV, while Philae is a more modest refrigerator-sized probe, which was launched about 10 years ago. Besides the instruments, the U.S. also provides about 45 scientists who shared the job of navigation to reach the comet - which proved to be a very difficult challenge.
"I take my hat off to the navigators, who achieved centimeter-precision control of the spacecraft over 400 million kilometers, which to me is mind-boggling."
The reason comets are interesting is because they were formed in the Solar System's "suburbs," far away from the degrading influence of the Sun, Chmielewski said. "Their material is pristine, it's frozen, and preserved for us to investigate. ... No matter how deep we dig in the earth, it's all processed material, because there has been so much volcanic activity, decomposition and so on, which has affected the material formed at the beginning, 4.6 million years ago."
In the second plenary talk, H. Nedwill Ramsey Professor Nader Engheta (University of Pennsylvania) described how his lab is expanding the properties of natural optical materials to create novel metamaterials with properties not found in nature. (Engheta is the 2015 SPIE Gold Medal winner.)
In electronics, controlling and manipulating flow of charged carriers has led to design of numerous functional devices, Engheta said. In photonics, by analogy, this is done through controlling photons and optical waves. The challenges and opportunities are different in the two fields.
Engheta's lab has demonstrated how waves can be confined to propagate along a single-atom-thick layer of graphene despite the wavelength of the light being larger than the height of the metamaterial surface.
These 2D metasurfaces lend themselves to being used to recreate typical wavelength guiding devices on the nano scale, such as optical splitters, fiber optic cables, and even wavelength guides. Optical metamaterials are used to create analogs of typical electronic components, such as resistors, capacitors, and inductors.
In preliminary experiments, the Engheta lab fabricated analog optical capacitors and inductors opening up the possibility for the future development of extremely fast optical integrated circuits.
An exciting aspect of Engheta's talk was the plethora of possibilities implied by his research. These include applications such as creating integrated optical circuits which can perform operations such as edge detection, finding the derivative of a function, or, thinking even further into the future, the creation of programmable optical integrated circuits.
|The plenary audience enjoys Chmielewski's descriptions of how characterizations of comet "67P" as duck-shaped permeated Rosetta mission conversation.
||SPIE President Toyohiko Yatagai (Utsunomiya University) welcomes participants to SPIE Optics + Photonics 2015.
What's next? Predictions on the next 60 years
SPIE is 60 years old this year -- and how the world has changed in that time. But what lies ahead? Student leaders who offered their predictions have visions for not only new photonics technology, but using the technology to find new ways for the world's people to live more harmoniously. See all the responses here.
Above, Goretti Hernandez, Yuliana Espinara, and Jorge Sanchez, Centro de Investigaciones en Óptica, offer a vision for improved healthcare.
Novel materials for OLEDs
The field of optical sources has developed rapidly since the use of incoherent sources such as tungsten lamps. From the development of coherent sources to the advances in mediums used to contain and amplify light, scientists continue to strive on improving optical source. While solid-state laser technology is an established field, research in novel materials which address some of the technology's shortcomings -- such as its low efficiency or bulky nature -- continues.
This and related research areas were discussed in opening sessions of the conference on Organic Light Emitting Materials and Devices.
Ken-Tsung Wong of Taiwan University gave a compelling talk (9566-5) on OLED efficiencies and the modalities of operation which include fluorescence, delayed-fluorescence, and phosphorescence, and introduced the work he and his team are doing on fabricating highly efficient blue OLEDs by mixing an exciplex cohost with a phosphorescent dopant system allowing for EQE of about 30.3
In the afternoon, Tae-Ho Kim from Samsung Advanced Institute of Technology showed how his lab group is researching how to efficiently manufacture quantum dots (QDs) at specific emission frequencies using a process suitable for industrial fabrication process (9566-13).
Typical quantum dot layers are created using typical solvent based printing. However such processes do not allow for the precise positioning of the layer need to create the arrays suitable for flat screen displays.
Wong discussed a new methodology known as a dry stamp process, in which profiles of the desired QD pattern are taken and stamped onto a substrate. He also demonstrated how his group developed a QD stacking sequence (B/G/B/R) which was able to reproduce all three wavelengths at varying drive voltages.
Biosensors for point-of-care
A talk by Maria Magliulo from the Università degli Studi di Bari Aldo Mulla (9568-206) in the conference on Organic Sensors and Bioelectronics reflected the high level of interest in optical research with promise for medical applications.
Magliulo presented work on an organic field effect transistor with a bio-electrolyte layer which allowed for the detection of molar concentrations as low as 4 x 10-15 moles. The ability to detect for such miniscule concentrations of a proteins is promising for possibility for bench-side testing, where doctors and health care technicians are limited by low concentrations of proteins of interest found in easily accessible body fluids such as saliva or tear drops.
The top-gated OFET described in Magliulo's talk is modelled as a series of three capacitors, with the biolayer containing the antibodies within an electrolyte solution having the lowest capacitance, leading to it having the highest effect on the current output. Thus the top-gated OFET becomes uniquely designed for detecting specifically low concentrations of proteins; the smaller the change in capacitances, the better the protein is detected.
Reducing light paths in holographic data storage
Optical data storage holography is becoming more prominent in research on optical data storage. However traditional holographic systems are generally complicated by their need for two beams -- both a reference and signal beam during the writing process. In holographic data storage, bit information is encoded in a diffraction grating written in a bulk material. This information is then read out by tuning a readout laser to the appropriate frequency and angular orientation.
Research reported by Ryuichi Katayama from Fukuoka Institute of Technology (9587-8) in the conference on Optical Data Storage showed a reduction in the number of light paths needed for writing in holographic data storage processes using of one of light's features: polarity.
In the configuration shown by Katayama, a radially polarized beam is used as the reference beam and the reference and signal beam are combined on the same side of the storage material. During the write process the two aligned beams are focused into the medium and a polarization specific diffraction grating is created.
This grating is then read during the readout process using circularly polarized light.
The work presented by Katayama hints at a great push for holographic storage medium to market by addressing one of the challenges of holographic data storage which are space and size constraints.
Let the games begin!
People's Choice winners: Instituto Nacional de Astrofisica, Optica,
The 2015 SPIE Optics Outreach Games featured 20 SPIE student chapters from all over the world demonstrating various optical phenomena to assist and inspire others.
Several chapters highlighted activities encouraging students to try optics experiments at home. The University of Exeter Chapter, for example, showed how to make a polariscope from broken polarized sunglasses, the screen from a calculator, or 3D movie glasses.
Many chapters utilized toys, household objects, and educational tools, demonstrating how outreach does not need to be an expensive endeavor. Indeed, Three Rivers Community College Chapter made “dumpster optics”; they use a cardboard tube and a CD to create an easy and inexpensive spectrometer.
The University of Laval Chapter demonstrated geometric optics with their house of shadows: students use objects of various sizes to cast shadows on pre-printed outlines to make fun shapes.
The night closed with an awards ceremony. Each chapter's outreach demonstration was judged and three winners were chosen.
Coming in third place was the Air Force Institute of Technology with their demonstration of how lasers can be utilized to etch or burn materials.
The University of Warsaw came in second place with their demonstration of a water droplet microscope and a small and simple spectrometer.
First place went to Washington State University with their do-it-yourself spectrometer activity focusing on how light interacts with materials and how to use spectra to learn what materials are made of.
The People's Choice award was presented to the Instituto Nacional de Astrofísica, Óptica y Electrónica for their excellent yet simple ripple tank demonstrating how waves interact to form constructive and destructive interference.
The breadth of optics activities covered by the 20 student chapters shows how outreach can be fun, inexpensive, elaborate, creative, or magical. The student chapters shared their passion and activities and hope to inspire others to present their outreach activities.
See more photos in the event gallery.
Coffee breaks and hallway conversations provide valuable opportunities to reconnect with long-time colleagues and become acquainted with new ones. (See more photos in the Optics + Photonics photo gallery.)
In the opening session in the conference on Metamaterials, Metadevices and Metasystems, Nikolay Zheludev of the UK Optoelectronics Research Center and Nanyang Technological University (9544-1) presented a brief history of toroidal excitations, their creation, observation, and uses.
Toroidal moments were first proposed to as a nuclear current, which participates in parity-violating weak interactions, in 1957. It was not until the 1980s that static toroidal moment studies really began, with dynamic studies beginning in 1990; there has since been a veritable explosion in the number of studies and papers in this field.
Toroidal moments are an entity distinct from electric and magnetic moments and add an additional family of multipole moments to established electromagnetic theory.
Although this response is very small in most materials due to electric and magnetic moments dominating the response, artificial materials can be specifically designed to enhance the toroidal response, as was first demonstrated by Marinoc, Boardman, Fedotov, and Zheludev in 2007 with a crystal of toroidal solenoids.
Dynamics anapoles have been experimentally observed and found to have a similar response to electromagnetic induced transparency.
Toroidal dipoles can be combined with electric dipoles to create a non-radiating source of a vector potential. Further, dynamic anapoles may be used to realize a dynamic experiment to test the Aharanov-Bohm effect. Even though the toroidal moment contributes minimally to “conventional” optical responses, it has been demonstrated to be an important factor in certain materials at very high frequencies.
One final interesting application of toroidal excitations is a “focused doughnut” pulse, described theoretically by inseparable time and space components, leading to very interesting behavior at high frequencies; the toroidal dipole dominates optical activities in dielectric nanoparticles with a specific index of refraction and a size comparable to the size of the pulse.
Enhancing undergrad lab expertise
Gabriel Spalding of Illinois Wesleyan University presented a current laboratory instructor mentoring program established and funded by the Advanced Laboratory Physics Association (ALPhA, www.advlab.org), in a presentation in the conference on Optical Trapping and Optical Micromanipulation (9548-7).
ALPhA currently finds a large disparity between undergraduate-level laboratory instruction and necessary knowledge of experimental methods required at the graduate level. Through a study of over 400 U.S. institutions, ALPhA finds most undergraduate institutions only require one or two advanced laboratory courses for an undergraduate degree. The program brings together small groups of laboratory instructors to teach them a specific advanced physics experiment, such as an optical trapping experiment, such that the instructors may return to their home institutions and teach the lab with confidence to their undergraduates.
Spalding encourages researchers to adapt their research in to an undergrad lab or to apply to instruct a 2.5-day session on already developed advanced undergraduate labs, such as optics labs. ALPhA provides funding to instructors and Spalding encourages researchers to apply.
Physics of Fabry-Perot cavities
In the Optical Trapping conference, Masud Mansuripur of the College of Optical Sciences, University of Arizona, discussed Fabry-Perot cavities and the physics of these setups (9548-8).
A Fabry-Perot cavity may be made from a stationary dielectric mirror and a perfectly reflecting mirror on a spring. Oscillations in the spring cause light coming in to the cavity to couple with the oscillating mirror, leading to interesting optical phenomena.
Fabry-Perot cavities behave like an optical notch filter in that certain wavelengths may pass through the cavity and other wavelengths are completely absorbed. This resonance is dependent on the length of the cavity, leading to highly tunable notch filters.
SETI: searching for life on other planets
Stuart Bowyer (University of California, Berkeley), in the conference on Instruments, Methods, and Missions for Astrobiology, discussed work on the search of extraterrestrial life (SETI), in which optics plays a key role (9606-8).
Using 21-cm radio emission, scientists are looking for beacons that are not of astronomical background and stand out against the general background. The wavelength is provides a unique marker for the presence of hydrogen, ubiquitous on our life-sustaining planet including in the material used to create life on Earth, DNA. Also, at this wavelength Earth's atmosphere is transparent, allowing for transmission into space as well as penetration through dust clouds that may be present around planets.
Optics does not provide the complete picture. Using the radio emission might point scientists in the right direction as to which planets would be interesting to explore but it does not definitively say whether there is or isn't life on other planets.
Bowyer's talk on SETI history was followed by an outlook on the future, presented by Eric Korpela, also of the University of California, Berkeley (9606-8) -- an outlook which only a few weeks ago would have made for a very different talk.
Several SETI initiatives have shut down in recent years, but at Berkeley, a new SETI research initiative called "Breakthrough Listen" was initiated in 2013, guaranteeing a substantial amount of observation time on three radio telescopes collectively covering the entire sky. Funding had become difficult to secure, but thanks a personal investment of $100 million by Yuri Milner and Stephen Hawking, funding has stabilized, Korpela reported.
Plans are to improve current equipment as well as the SETI@home initiative, which makes use of participants' idle processor time to process enormous amounts of data the project receives. Apart from technical improvements, like multithreading and making better use of GPU power, they will also develop an iOS version and invest in reaching out to more people to increase the processing power of the initiative.
Getting the latest information
A suite of more than three dozen courses and workshops being offered at SPIE Optics + Photonics provides an excellent means of learning about new techniques and exploring new fields. New and featured courses this year cover Probability for Systems Engineers, Gradient Index Optical Design, Optical Alignment, and other topics.
Star tech: the next generation
|SPIE Student Chapter leaders on the Coronado Terrace at the San Diego Marriott Marquis Hotel and Marina
Nearly 250 SPIE student chapter leaders from around the world gathered at the San Diego Marriott Marquis and Marina to kick off Optics + Photonics.
During the highly interactive, all-day event facilitated by Jean-luc Doumont (Louvain and Stanford), students discussed what being a leader is all about (and what it is not about), how to communicate across cultures, and how to go from ideas to achievements.
Teams formed to brainstorm what leadership means, drew their ideas on paper, and presented in front of the group. See a few of their ideas in the Optics + Photonics photo gallery.
All photos © SPIE, the international society for optics and photonics, except where noted.