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Choi K.K.,U.S. Army | Jhabvala M.D.,NASA | Forrai D.P.,L3 Cincinnati Electronics | Sun J.,U.S. Army | Endres D.,L3 Cincinnati Electronics
Infrared Physics and Technology | Year: 2011

We have extended our investigation of corrugated quantum well infrared photodetector focal plane arrays (C-QWIP FPAs) into the far infrared regime. Specifically, we are developing the detectors for the thermal infrared sensor (TIRS) used in the NASA Landsat Data Continuity Mission. This mission requires infrared detection cutoff at 12.5 μm and FPAs operated at ∼43 K. To maintain a low dark current in these extended wavelengths, we adopted a low doping density of 0.6 × 1018 cm-3 and a bound-to-bound state detector in one of the designs. The internal absorption quantum efficiency η is calculated to be 25.4% for a pixel pitch of 25 μm and 60 periods of QWs. With a pixel fill factor of 80% and a substrate transmission of 70.9%, the external η is 14.4%. To yield the theoretical conversion efficiency CE, the photoconductive gain was measured and is 0.25 at 5 V, from which CE is predicted to be 3.6%. This value is in agreement with the 3.5% from the FPA measurement. Meanwhile, the dark current is measured to be 2.1 × 10-6 A/cm2 at 43 K. For regular infrared imaging above 8 μm, the FPA will have a noise equivalent temperature difference (NETD) of 16 mK at 2 ms integration time in the presence of 260 read noise electrons, and it increases to 22 mK at 51 K. The highest operability of the tested FPAs is 99.967%. With the CE agreement, we project the FPA performance in the far infrared regime up to 30-μm cutoff, which will be useful for the Jupiter-Europa deep space exploration. In this work, we also investigated the C-QWIP optical coupling when the detector substrate is thinned. © 2010 Elsevier Ltd. All rights reserved. Source


Choi K.-K.,U.S. Army | Sun J.,NASA | Jhabvala M.D.,L3 Cincinnati Electronics | Forrai D.P.,U.S. Army | Endres D.W.,L3 Cincinnati Electronics
Optical Engineering | Year: 2011

We have extended our investigation of corrugated quantum well infrared photodetector focal plane arrays (FPAs) into the far infrared regime. Specifically, we are developing the detectors for the thermal infrared sensor (TIRS) used in the Landsat Data Continuity Mission. To maintain a low dark current, we adopted a low doping density of 0.6×1018cm 3 and a bound-to-bound state detector. The internal absorption quantum efficiency (QE) is calculated to be 25.4%. With a pixel fill factor of 80% and a substrate transmission of 70.9%, the external QE is 14.4%. To yield the theoretical conversion efficiency (CE), the photoconductive gain was measured and is 0.25 at 5 V, from which CE is predicted to be 3.6%. This value is in agreement with the 3.5% from the FPA measurement. Meanwhile, the dark current is measured to be 2.1×106 A/cm2 at 43 K. For regular infrared imaging above 8 μm, the FPA will have an noise equivalent temperature difference (NETD) of 16 mK at 2 ms integration time in the presence of 260 read noise electrons. The highest operability of the tested FPAs is 99.967%. With the CE agreement, we project the FPA performance in the far infrared regime up to 30 μm cutoff. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). Source


Nichols J.M.,U.S. Navy | Waterman J.R.,U.S. Navy | Menon R.,RemoteReality Corporation | Devitt J.,L3 Cincinnati Electronics
Optical Engineering | Year: 2010

A high-resolution midwave infrared panoramic periscope sensor system has been developed. The sensor includes an f2.5 catadioptric optical system that provides a field of view with 360-deg horizontal azimuth and -10- to 30-deg elevation without requiring moving components (e.g., rotating mirrors). The focal plane is a 20482048, 15-μm-pitch InSb detector operating at 80 K. An onboard thermoelectric reference source allows for real-time nonuniformity correction using the two-point correction method. The entire system (detector-Dewar assembly, cooler, electronics, and optics) is packaged to fit in an 8-in.-high, 6.5-in.-diameter volume. This work describes both the system optics and the electronics and presents sample imagery. We model both the sensors radiometric performance, quantified by the noise-equivalent temperature difference, and its resolution performance. Model predictions are then compared with estimates obtained from experimental data. The ability of the system to resolve targets as a function of imaged spatial frequency is also presented. © 2010 Society of Photo-Optical Instrumentation Engineers. Source


Home > Press > Nanostructures promise big impact on higher-speed, lower-power optical devices: University of Cincinnati physicists are seeing big potential in small semiconductor nanowires for improved optical infrared sensor technologies Abstract: With new technology getting smaller and smaller, requiring lower power, University of Cincinnati physics research points to new robust electronic technologies using quantum nanowire structures. The semiconductor nanowires may lead to advances in sensitive electronic technology including heat detecting optical infrared sensors and biomedical testing, all of which can fit inside small electrical devices. Supported by multiple National Science Foundation grants, the UC research team is working with a collaborative team of physicists, electronic materials engineers and doctoral students from around the world -- all to perfect the growth and development of crystalline nanowires that could form the backbone of new nanotechnologies. But to fully apply this technology to modern devices, UC researchers are first looking closely -- on a fundamental level -- at how energy is distributed and measured along thin-strand nanowires so small that thousands of them could theoretically fit inside a human hair. "Now that we know the technology can be developed, we need to understand exactly how the electrical processes work inside the nanowire cores," say Howard Jackson and Leigh Smith, professors of physics at the University of Cincinnati. "After finally perfecting a standardized process for growing and developing crystalline nanowire fibers with our partners at the Australian National University in Canberra, we have been able to take it one step further. "Using a combination of materials like indium gallium arsenide and indium phosphide, we can develop thin nanowire cores with protective outer shells." It turns out that these unique nanowire materials have unusually large spin orbit interactions, which the researchers find can conduct electricity really well and may allow the use of spin to enable new computing paradigms. Jackson and Smith are presenting these findings at the American Physical Society Conference, in Baltimore, March 16, titled, "Exploring Dynamics and Band Structure in Mid Infrared GaAsSb and GaAsSb/InP Nanowire Heterostructures." SMALL YET MIGHTY The researchers claim the secret to the success of this multi-collaborative effort is in the combination of materials used to create the nanowires. Initially grown at the Australian National University in Canberra, the nanowires are sprouted from a combination of beads of molten gold scattered across a particular surface. As the process is heated inside a chamber using indium gallium arsenide gases, long microscopically thin core fibers sprout up from between the controlled surface environment. Other material combinations are then introduced to form an outer shell acting as a sheath around each core, resulting in quantum nanowire semiconducting heterostructures all uniform in size, shape and behavior. After the fibers are shipped across the globe to Cincinnati, Jackson, Smith and their team of doctoral students are then able to use sophisticated equipment to measure the electrical and photovoltaic potentials of each fiber along its surface. In earlier research, the collaborative team found extrinsic and intrinsic problems when the fiber cores did not have the outer sheath-like shells. "If we don't have this outer sheath, the nanowires have a very short energy lifetime, says Jackson. "When we surround the core with this sheath, the energy lifetime can go up by an order or two orders of magnitude." And while gallium arsenide alone is a very common semiconductor, its energy gap is large and in the visible range, which absorbs light. To achieve success in detecting optical heat or infrared, the team says using indium gallium arsenide fibers have smaller energy gaps that can be used successfully in optical detector devices. doctoral student in physics lab with laser lights "The goal for one of our research equipment grants is to work with the local L3 Cincinnati Electronics Company, which makes infrared (small gap) detectors for night-vision imaging for military applications," says Smith. "Future direct applications for this type of technology also include medical devices that detect body heat, as well as remote sensors installed in iphones that can be used for environmental purposes that detect and measure heat loss in houses." The researchers say this new nanowire technology is unique because it can turn different wavelengths of light into an electrical signal, and in this case it means turning an infrared light into an electric signal that can be measured. Smith explains that with the geometry of the nanowires you can have a long axis running the length of the wire, which gives you lots of possibilities for absorption as the light comes down, but then you also have this very small diameter. "When contacts are interspersed along either side, essentially then the electrons in the holes don't have to travel very far before they are collected," says Smith. "So in principle it can become a more effective detector as well as a more effective solar cell." SMALL DIMENSION NANOWIRES "When you get to very small dimensions in nanowires that are small in diameter, but are a few microns long, those properties then change and can show quantum properties and become almost one-dimensional," says Jackson. "The physics then changes as you change those sizes." Jackson and Smith found that the nanowire's ultra-thin outer shells functioned best at widths of four to eight nanometers, which is 25,00 and 12,500 times smaller respectively, than the diameter of a human hair. When looking at the overarching benefits of working with microscopic nanostructures the researchers see tremendous potential for its ability to pack much more high-energy efficiency into small devices with finite space. It's getting closer to a win-win for everyone, they're saying, especially when this research enters the next stage, bringing it closer to functioning inside electronic and optical sensor devices. "Our fundamental investigation is still a step away from a direct optical device application," says Jackson. "But you can clearly see over time that this collaborative research has made an impact." ### Additional contributors to the research are UC physics doctoral students, Nadeeka Wickramasuriya, Yuda Wang and Samuel Linser. Collaborators from the Australian National University in Canberra, Department of Electronic Materials Engineering, are Xiaoming Yuan, Philippe Caroff, Hoe Tan and Chennupati Jagadish. NSF FUNDING * NSF "Major Research Instrumentation: Development of a Mid-infrared Optical Microscope for Investigation of Femtosecond Dynamics of Single Large Spin Orbit Semiconductor Heterostrucutures," Leigh Smith and Howard Jackson, $492,983 plus cost sharing of $201,798 or a total of $694,781. * NSF "MRI: Acquisition of a Ultra-High Resolution Analytical Scanning Electron Microscope for Multidisciplinary Research and Education," V. Vasudevan, PI, several co-PIs including L. Smith and H. Jackson, $531,693 plus significant cost sharing from the State of Ohio and CEAS and A&S to bring the total to >$900,000. * NSF "GOALI: Infrared Nanowire Heterostructures: Fundamentals and Emerging Detector Applications," Leigh Smith and Howard Jackson, $400,000. * NSF DMR "Carrier and Spin Dynamics in Large Spin-Orbit Semiconductor Nanowire Heterostructures," Leigh Smith and Howard Jackson, $489,551. Teaching and Broader Impacts: * NSF-IUSE "Enhancing Student Success in Biology, Chemistry, and Physics by Transforming the Faculty Culture," H. Jackson, PI, $97,148. This grant is provided as a supplement to a presently funded grant for Biology, Chemistry, and Physics so that the Department of Mathematics can be included in these efforts. The currently funded grant is NSF-IUSE "Enhancing Student Success in Biology, Chemistry, and Physics by Transforming the Faculty Culture," $643,000, 9/01/2014 - 8/31/2018, Howard Jackson (PI). * NSF Collaborative Research: Resource and Repository: Broader Impacts of the NSF-CMP Program, Leigh Smith and others $150,000. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


GLENDALE, Calif.--(BUSINESS WIRE)--Disney Consumer Products will unveil unique product experiences and exclusive merchandise at this year’s D23 EXPO, Disney’s ultimate fan event, held at the Anaheim Convention Center August 14–16. Reflecting a ‘Tradition Meets Innovation’ theme, the expansive Disney Consumer Products pavilion will provide interactive opportunities for fans of all ages to explore exciting stories and engaging experiences and products celebrating everyone’s favorite Disney, Pixar, Marvel, and Star Wars stories. Throughout the weekend, Disney Consumer Products will give fans the chance to get hands-on with the very latest in product innovations, explore fashion trends, books, apps, and more, as well as shop for collectible Disney Store merchandise at D23 EXPO. Special artist signings and stage presentations also will take place over the three-day event, offering fans the chance to get up close and personal with their favorite storytellers. Events and attractions within the Disney Consumer Products pavilion include: In addition to the exciting events and attractions offered in the Disney Consumer Products pavilion, the Disney Store shop at D23 EXPO invites attendees to shop an array of special products not yet available to the general public. Showcased throughout more than 3,000 sq. ft. of retail space, new collections and Limited Edition items will launch throughout the D23 EXPO weekend. Offering even more collectible merchandise, Disney Store will be launching “Disney 3D Print Studio” at D23 EXPO, offering fans the chance to personalize new figures, including a Disney Mouseketeer, Star Wars stormtrooper, and Marvel’s Iron Man, with their likeness through the use of facial-scanning kiosks. Marking the first foray into 3D printing by Disney Store, the figures sold at EXPO will feature unique packaging with a special D23 Certificate of Authenticity. More details about Disney Store merchandise offered at EXPO will be released in the coming weeks. Disney Publishing will take fans into the world of books, apps, and everything in between by showcasing how artists, storytelling, and innovative content come together to create stories full of magic and adventure. Disney Publishing will also present in Stage 28 at D23 EXPO. Located inside the Disney Consumer Products pavilion, Stage 28 will feature exciting presentations and author signings including: Additional details and updates about Disney Consumer Products events and activities will continue to be updated on www.D23EXPO.com, on Facebook, and Twitter at “DisneyD23.” Tickets for D23 EXPO 2015 are available at a discounted price for a limited time. Now through June 30, 2015, tickets are $67 for one-day adult admission and $48 for children 3–12. Tickets for members of D23: The Official Disney Fan Club are $58 for one-day adult admission and $42 for children. Multi-day money-saving tickets are also available. D23 Members can save as much as $188 off the price of admission, based on the purchase of four three-day tickets at the D23 Member rate. For more information on tickets and the ticket pricing structure for D23 Members and general admission, visit D23EXPO.com. Disney Consumer Products (DCP) is the business segment of The Walt Disney Company (NYSE:DIS) that delivers innovative and engaging product experiences across thousands of categories from toys and apparel to books and fine art. As the world’s largest licensor, DCP inspires the imaginations of people around the world by bringing the magic of Disney into their homes. DCP is comprised of three business units: Licensing, Publishing and Disney Store. The Licensing business is aligned around five strategic brand priorities: Disney Media, Classics & Entertainment, Disney & Pixar Animation Studios, Disney Princess & Tinker Bell, Lucasfilm and Marvel. Disney Publishing Worldwide (DPW) is the world’s largest publisher of children’s books, magazines, eBooks and apps. DPW is also committed to the educational development of children around the world through Disney Learning, which includes our flagship learning brand, Disney Imagicademy, as well as Disney English and other Disney-themed learning products. The Disney Store retail chain operates across North America, Europe, and Japan with more than 350 stores and provides high-quality, unique products. Disney Store also operates ecommerce sites in several countries, which can be found here. For more information, please visit www.DisneyConsumerProducts.com. D23 EXPO—The Ultimate Disney Fan Event—brings together all the worlds of Disney under one roof for three packed days of presentations, pavilions, experiences, concerts, sneak peeks, shopping, and more. The event provides fans with unprecedented access to Disney films, television, games, theme parks, and celebrities. For the latest D23 EXPO 2015 news, visit D23EXPO.com. Presentations, talent, and schedule subject to change. To join the D23 EXPO conversation, make sure to follow DisneyD23 on Twitter, Facebook, Pinterest, Instagram, and YouTube, and use the hashtag #D23EXPO. The name “D23” pays homage to the exciting journey that began in 1923 when Walt Disney opened his first studio in Hollywood. D23 is the first official club for fans in Disney’s 90-plus-year history. It gives its members a greater connection to the entire world of Disney by placing them in the middle of the magic through its quarterly publication, Disney twenty-three; a rich website at D23.com with members-only content; member-exclusive discounts; and special events for D23 Members throughout the year. Fans can join D23 at Gold and General Membership levels at D23.com and at DisneyStore.com/D23. To keep up with all the latest D23 news and events, follow DisneyD23 on Twitter, Facebook, Pinterest, and YouTube.

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