Title: Demonstration of quantum network protocols over a 14-km urban fiber link<\/h3>\n
1<\/sup>Experimentalphysik, Universit\u00e4t des Saarlandes, Saarbr\u00fccken, Germany. 2<\/sup>Luxembourg Institute of Science and Technology (LIST), Belveaux, Luxembourg. 3<\/sup>Menlo Systems GmbH, Planegg, Germany.<\/em><\/p>\n We report on the implementation of quantum entanglement distribution and quantum state teleportation over a 14.4 km urban dark-fiber link, which is partially underground, partially overhead, and patched in several stations. We characterize the link for its use as a quantum channel and realize its active polarization stabilization. Using a type-II cavity-enhanced SPDC photon pair source, a 40<\/sup>Ca+<\/sup> single-ion quantum memory, and quantum frequency conversion to the telecom C-band, we demonstrate photon-photon entanglement, ion-photon entanglement, and teleportation of a qubit state from the ion onto a remote telecom photon, all realized over the urban fiber link.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n 1<\/sup>Center for Photonic Communication and Computing, Department of Electrical and Computer Engineering, Northwestern University, 2145 N. Sheridan Rd., Evanston, IL 60208, USA. 2<\/sup>NuCrypt, LLC, 1460 Renaissance Dr #205, Park Ridge, IL 60068, USA. 3<\/sup>Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.<\/em><\/p>\n The scalability of quantum networking will benefit from quantum and classical communications coexisting in shared fibers, the main challenge being spontaneous Raman scattering noise. We investigate the coexistence of multi-channel O-band quantum and C-band classical communications. We characterize multiple narrowband entangled photon pair channels across 1282 nm-1318 nm co-propagating over 48 km of installed standard fiber with record C-band power (>18 dBm) and demonstrate that some quantum-classical wavelength combinations significantly outperform others. We analyze the Raman noise spectrum, optimal wavelength engineering, multi-photon pair emission in entangled photon-classical coexistence, and evaluate the implications for future quantum applications.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n 1<\/sup>James C. Wyant College of Optical Sciences, University of Arizona, Tucson, AZ Quantum receivers aim to effectively navigate the vast quantum-state space to endow quantum information processing capabilities unmatched by classical receivers. To date, only a handful of quantum receivers have been constructed to tackle the problem of discriminating coherent states. Quantum receivers designed by analytical approaches, however, are incapable of effectively adapting to diverse environmental conditions, resulting in their quickly diminishing performance as the operational complexities increase. Here, we present a general architecture, dubbed the quantum receiver enhanced by adaptive learning, to adapt quantum receiver structures to diverse operational conditions. The adaptively learned quantum receiver is experimentally implemented in a hardware platform with record-high efficiency. Combining the architecture and the experimental advances, the error rate is reduced up to 40% over the standard quantum limit in two coherent-state encoding schemes.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n 1<\/sup>Deutsches Zentrum f\u00fcr Luft- und Raumfahrt, Institut f\u00fcr Physik der Atmosph\u00e4re, Oberpfaffenhofen, Germany. 2<\/sup>Deutsches Zentrum f\u00fcr Luft- und Raumfahrt, Institut f\u00fcr Solar-Terrestrische Physik, Neustrelitz, Germany.<\/em><\/p>\n Monitoring and predicting space weather activity is increasingly important given society\u2019s growing reliance on space-based infrastructure but is hampered by a lack of observational data. Airglow at 1083 nm from metastable helium He(23<\/sup>S) in the thermosphere has long been a target for remote-sensing instruments seeking to fill that gap; however, passive measurements of He(23<\/sup>S) fluorescence are limited by low brightness, and interpretation of these observations is complicated by the > 500 km depth of the He(23<\/sup>S) layer. Here, we demonstrate a lidar instrument that is able to stimulate and detect He(23<\/sup>S) fluorescence, and we present measured profiles of He(23<\/sup>S) density. These measurements provide crucial validation to space weather models, support predictions of peak number density ( ~ 1 cm-3<\/sup>) and the dependence of density on altitude, solar zenith angle, and season, and extend by a factor of 4 the maximum probed altitude range by an atmospheric profiling lidar. These measurements open the door for the development of more sophisticated lidars: by applying well-established spectroscopic lidar techniques, one can measure the Doppler shift and broadening of the He(23<\/sup>S) line, thereby retrieving profiles of neutral wind speed and temperature, opening a window for studying space weather phenomena.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n 1<\/sup>Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.2<\/sup>Massachusetts Institute of Technology Lincoln Laboratory, Lexington, MA, United States.3<\/sup>Massachusetts Institute of Technology, Health Sciences and Technology Program, Cambridge, MA, United States.<\/em><\/p>\n Time-domain diffuse correlation spectroscopy (TD-DCS) offers a novel approach to high-spatial resolution functional brain imaging based on the direct quantification of cerebral blood flow (CBF) changes in response to neural activity. However, the signal-to-noise ratio (SNR) offered by previous TD-DCS instruments remains a challenge to achieving the high temporal resolution needed to resolve perfusion changes during functional measurements. Here we present a next-generation optimized functional TD-DCS system that combines a custom 1,064 nm pulse-shaped, quasi transform-limited, amplified laser source with a high-resolution time-tagging system and superconducting nanowire single-photon detectors (SNSPDs). System characterization and optimization was conducted on homogenous and two-layer intralipid phantoms before performing functional CBF measurements in six human subjects. By acquiring CBF signals at over 5 Hz for a late gate start time of the temporal point spread function (TPSF) at 15 mm source-detector separation, we demonstrate for the first time the measurement of blood flow responses to breath-holding and functional tasks using TD-DCS.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n 1<\/sup>Massachusetts General Hospital, Harvard Medical School, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Boston, Massachusetts, USA. 2<\/sup>Massachusetts Institute of Technology, Health Sciences and Technology Program, Cambridge, Massachusetts, USA. 3<\/sup>Massachusetts Institute of Technology Lincoln Laboratory, Lexington, Massachusetts, USA.<\/em><\/p>\n Significance:<\/strong> The ability of diffuse correlation spectroscopy (DCS) to measure cerebral blood flow (CBF) in humans is hindered by the low signal-to-noise ratio (SNR) of the method. This limits the high acquisition rates needed to resolve dynamic flow changes and to optimally filter out large pulsatile oscillations and prevents the use of large source-detector separations (\u22653 cm), which are needed to achieve adequate brain sensitivity in most adult subjects. Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n 1<\/sup>Department of Biomedical Engineering, Wright State University, Dayton, OH 45435, USA. 2<\/sup>Quantum Opus, LLC, Novi, MI 48375, USA. 3<\/sup>Department of Neurology & Rehabilitation Medicine, University of Cincinnati, Cincinnati, OH 45267, USA.<\/em><\/p>\n Survivors of severe brain injury may require care in a neurointensive care unit (neuro-ICU), Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n Authors: Han-Sen Zhong1,2<\/sup>, Hui Wang1,2<\/sup>, Yu-Hao Deng1,2<\/sup>, Ming-Cheng Chen1,2<\/sup>, Li-Chao Peng1,2<\/sup>, Yi-Han Luo1,2<\/sup>, Jian Qin1,2<\/sup>, Dian Wu1,2<\/sup>, Xing Ding1,2<\/sup>, Yi Hu1,2<\/sup>, Peng Hu3<\/sup>, Xiao-Yan Yang3<\/sup>, Wei-Jun Zhang3<\/sup>, Hao Li3<\/sup>, Yuxuan Li4<\/sup>, Xiao Jiang1,2<\/sup>, Lin Gan4<\/sup>, Guangwen Yang4<\/sup>, Lixing You3<\/sup>, Zhen Wang3<\/sup>, Li Li1,2<\/sup>, Nai-Le Liu1,2<\/sup>, Chao-Yang Lu1,2<\/sup>, Jian-Wei Pan1,2<\/sup><\/p>\n 1<\/sup>Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. 2<\/sup>CAS Centre for Excellence and Synergetic Innovation Centre in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China. 3<\/sup>State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. 4<\/sup>Department of Computer Science and Technology and Beijing National Research Center for Information Science and Technology, Tsinghua University, Beijing 100084, China.<\/em><\/p>\n Quantum computers promise to perform certain tasks that are believed to be intractable to classical computers. Boson sampling is such a task and is considered a strong candidate to demonstrate the quantum computational advantage. We performed Gaussian boson sampling by sending 50 indistinguishable single-mode squeezed states into a 100-mode ultralow-loss interferometer with full connectivity and random matrix\u2014the whole optical setup is phase-locked\u2014and sampling the output using 100 high-efficiency single-photon detectors. The obtained samples were validated against plausible hypotheses exploiting thermal states, distinguishable photons, and uniform distribution. The photonic quantum computer,\u00a0<\/span>Jiuzhang<\/i>, generates up to 76 output photon clicks, which yields an output state-space dimension of 10<\/span>30<\/sup>\u00a0and a sampling rate that is faster than using the state-of-the-art simulation strategy and supercomputers by a factor of ~10<\/span>14<\/sup>.<\/span><\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n NASA Glenn Research Center 21000 Brookpark Road, Cleveland, Ohio 44135, USA.<\/em><\/p>\n The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is developing a low cost, scalable, photon-counting receiver prototype for space-to-ground optical communications links. The receiver is being tested in a test bed that emulates photon-starved space-to-ground optical communication links. The receiver uses an array of single-pixel fiber coupled superconducting nanowire single-photon detectors. The receiver is designed to receive the high photon efficiency serially concatenated pulse position modulation (SCPPM) waveform specified in the Consultative Committee for Space Data Systems (CCSDS) Optical Communications Coding and Synchronization Blue Book Standard. The optical receiver consists of an array of single-pixel superconducting nanowire detectors, analog phase shifters for channel alignment, digitizers for each detector channel, and digital processing of the received signal. An overview of the test bed and arrayed receiver system is given. Simulation and system characterization results are presented. The data rate increase of using a four-channel arrayed detector system over using one single pixel nanowire detector is characterized. Results indicate that a single-pixel detector is capable of receiving data at a rate of 40 Mbps and a four-channel arrayed detector system is capable of receiving data at a rate of 130 Mbps.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n 1<\/sup>Department of Electrical and Computer Engineering, Center for Photonic Communication and Computing, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3118, USA. 2<\/sup>CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816, USA. 3<\/sup>Currently with the Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA, and the University of Maryland, College Park, Maryland 20742, USA. 4<\/sup>Currently with Elenion Technologies, 171 Madison Ave #1100, New York, NY 10016, USA.<\/em><\/p>\n An efficient source of quantum-correlated photon-pairs that is integrable with existing silicon-electronics fabrication techniques is desirable for use in quantum photonic integrated circuits. Here we demonstrate signal-idler photon pairs with high coincidence-to-accidental count ratios of over 103 on a coarse wavelength-division-multiplexing grid that spans 140 nm by using a 300-\u00b5m-long poled region in a thin-film periodically-poled lithium-niobate ridge waveguide bonded to silicon. The pairs are generated via spontaneous parametric downconversion pumped by a continuous-wave tunable laser source. The small mode area of the waveguide allows for efficient interaction in a short length of the waveguide and, as a result, permits photon-pair generation over a broad range of signal-idler wavelengths.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n NASA Glenn Research Center 21000 Brookpark Road, Cleveland, Ohio 44135, USA.<\/em><\/p>\n We present a scalable design for a photon-counting ground receiver based on superconducting nanowire single photon detectors (SNSPDs) and field programmable gate array (FPGA) real-time processing for applications to space-to-ground photon starved links, such as the Orion EM-2 Optical Communication Demonstration (O2O), and future deep space or low transmitter power missions. The receiver is designed to receive a serially concatenated pulse position modulation (SCPPM) waveform, which follows the Consultative Committee for Space Data Systems (CCSDS) Optical Communications Coding and Synchronization Red Book standard. The receiver design uses multiple individually fiber coupled, 80% detection efficiency commercial SNSPDs in parallel to scale to a required data rate, and is capable of achieving data rates up to 528 Mbps. For efficient fiber coupling from the telescope to the array of parallel detectors that can be scaled both to telescope aperture size and the number of detectors, we use either a single mode fiber (SMF) photonic lantern or a few-mode fiber (FMF) photonic lantern. In this paper we give an overview of the receiver system design, the characteristics of the photonic lanterns, the performance of the SNSPDs, and system level tests. We show that 40 Mbps can be received using a single SNSPD, and discuss aspects for scaling to higher data rates.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n Authors: Timothy L. Atallah, Anthony V. Sica, Ashley J. Shin, Hannah C. Friedman, Justin R. Caram<\/p>\n Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, USA<\/em><\/p>\n We describe and implement an interferometric approach to decay associated photoluminescence spectroscopy, which we term decay associated Fourier spectroscopy (DAFS). In DAFS, the emitted photon stream from a substrate passes through a variable path length Mach-Zehnder interferometer prior to detection and timing. The interferometer encodes spectral information in the intensity measured at each detector enabling simultaneous spectral and temporal resolution. We detail several advantages of DAFS, including wavelength-range insensitivity, drift-noise cancellation, and optical mode retention. DAFS allows us to direct the photon stream into an optical fiber, enabling the implementation of superconducting nanowire single photon detectors for energy-resolved spectroscopy in the shortwave infrared spectral window (\u03bb=1-2 \u03bcm). We demonstrate the broad applicability of DAFS, in both the visible and shortwave infrared, using two F\u00f6rster resonance energy transfer pairs: a pair operating with conventional visible wavelengths and a pair showing concurrent acquisition in the visible and the shortwave infrared regime.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n Authors: Brian E. Vyhnalek, Sarah A. Tedder, Evan J. Katz, and Jennifer M. Nappier<\/p>\n National Aeronautics and Space Administration, Glenn Research Center, Cleveland, OH, USA.<\/em><\/p>\n The NASA Glenn Research Center\u2019s development of a high-photon efficiency real-time optical communications ground receiver has added superconducting nanowire single-photon detectors (SNSPDs) coupled with few-mode fibers (FMF). High data rate space-to-ground optical communication links require enhanced ground receiver sensitivity to reduce spacecraft transmitter constraints, and therefore require highly efficient coupling from fiber to detector. In the presence of atmospheric turbulence the received optical wavefront can be severely distorted introducing higher-order spatial mode components to the received signal. To reduce mode filtering and mismatch loss and the resulting degradations to detector coupling efficiency, we explore the use of few-mode fiber coupling to commercial single-pixel SNSPDs. Graded index 20-\u00b5m few-mode fibers allow the commercial single pixel SNSPD\u2019s active area to couple with equal efficiency as single mode fibers. Here we determine detector characteristics such as count rate, detection efficiency, dark counts, and jitter, as well as detection efficiencies for higher-order fiber spatial modes. Additionally, we assess the laboratory performance of the detectors in an optical system which emulates future deep space optical communications links.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n Authors: Massimiliano Proietti1<\/sup>, Alexander Pickston1<\/sup>, Francesco Graffitti1<\/sup>, Peter Barrow1<\/sup>, Dmytro Kundys1<\/sup>, Cyril Branciard2<\/sup>, Martin Ringbauer1,3<\/sup>, and Alessandro Fedrizzi1<\/sup><\/p>\n 1<\/sup>Scottish Universities Physics Alliance (SUPA), Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK. 2<\/sup>Universit\u00e9 Grenoble Alpes, CNRS, Grenoble INP, Institut N\u00e9el, 38000 Grenoble, France. 3<\/sup>Institut f\u00fcr Experimentalphysik, Universit\u00e4t Innsbruck, 6020 Innsbruck, Austria.<\/em><\/p>\n The scientific method relies on facts, established through repeated measurements and agreed upon universally, independently of who observed them. In quantum mechanics, the objectivity of observations is not so clear, most dramatically exposed in Eugene Wigner\u2019s eponymous thought experiment where two observers can experience fundamentally different realities. While observer-independence has long remained inaccessible to empirical investigation, recent no-go theorems construct an extended Wigner\u2019s friend scenario with four entangled observers that allows us to put it to the test. In a state-of-the-art 6-photon experiment, we here realise this extended Wigner\u2019s friend scenario, experimentally violating the associated Bell-type inequality by 5 standard deviations. This result lends considerable strength to interpretations of quantum theory already set in an observer-dependent framework and demands for revision of those which are not.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n 1<\/sup>School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK. 2<\/sup>School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK. 3<\/sup>Department of Physics, University of Warwick, Coventry CV4 7AL, UK.<\/em><\/p>\n When two indistinguishable photons are each incident on separate input ports of a beamsplitter, they \u201cbunch\u201d deterministically, exiting via the same port as a direct consequence of their bosonic nature. This two-photon interference effect has long-held the potential for application in precision measurement of time delays, such as those induced by transparent specimens with unknown thickness profiles. However, the technique has never achieved resolutions significantly better than the few-femtosecond (micrometer) scale other than in a common-path geometry that severely limits applications. We develop the precision of Hong-Ou-Mandel interferometry toward the ultimate limits dictated by statistical estimation theory, achieving few-attosecond (or nanometer path length) scale resolutions in a dual-arm geometry, thus providing access to length scales pertinent to cell biology and monoatomic layer two-dimensional materials.<\/p>\n Full Paper<\/a><\/p>\n<\/div>\n <\/p>\n Authors: Christian Reimer, Michael Kues, Piotr Roztocki,\u00a0Benjamin Wetzel, Fabio Grazioso,\u00a0Brent E. Little,\u00a0Sai T. Chu,\u00a0Tudor Johnston,\u00a0Yaron Bromberg,\u00a0Lucia Caspani,\u00a0David J. Moss,\u00a0Roberto Morandotti<\/p>\n Institut National de la Recherche Scientifique\u2013\u00c9nergie Mat\u00e9riaux T\u00e9l\u00e9communications\u00a0<\/em>![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2024\/11\/Demonstration-of-quantum-network.png\")
Authors: Stephan Kucera1,2<\/sup>, Christian Haen1<\/sup>, Elena Arensk\u00f6tter1<\/sup>, Tobias Bauer1<\/sup>, Jonas Meiers1<\/sup>, Marlon Sch\u00e4fer1<\/sup>, Ross Boland3<\/sup>, Milad Yahyapour3<\/sup>, Maurice Lessing3<\/sup>, Ronald Holzwarth3<\/sup>, Christoph Becher1<\/sup>, and J\u00fcrgen Eschner1<\/sup><\/p>\nAbstract<\/h4>\n
Title: Designing noise-robust quantum networks coexisting in the classical fiber infrastructure<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2024\/11\/Designing-noise-robust-quantum-networks.png\")
Authors: Jordan M. Thomas1<\/sup>, Gregory S. Kanter1,2<\/sup>, and Prem Kumar1,3<\/sup><\/p>\nAbstract<\/h4>\n
Title: Quantum receiver enhanced by adaptive learning<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/12\/41377_2022_1039_Fig3_HTML.png\")
Authors: Chaohan Cui1<\/sup>, William Horrocks1<\/sup>, Shuhong Hao2<\/sup>, Saikat Guha1,3<\/sup>, Nasser Peyghambarian1,2<\/sup>, Quntao Zhuang1,3,4<\/sup>, and Zheshen Zhang1,2,3,5<\/sup><\/p>\n
85721, USA. 2<\/sup>Department of Materials Science and Engineering, University of
Arizona, Tucson, AZ 85721, USA. 3<\/sup>Department of Electrical and Computer
Engineering, University of Arizona, Tucson, AZ 85721, USA. 4<\/sup>Department of
Electrical and Computer Engineering, University of Southern California, Los
Angeles, CA 90089, USA. 5<\/sup>Department of Electrical Engineering and Computer
Science, University of Michigan, Ann Arbor, MI 48109, USA.<\/em><\/p>\nAbstract<\/h4>\n
Title: Measurements of metastable helium in Earth\u2019s atmosphere by resonance lidar<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2024\/11\/Measurements-of-metastable-helium-in.png\")
Authors: Bernd Kaifler1<\/sup>, Christopher Geach2<\/sup>, Hans Christian B\u00fcdenbender1<\/sup><\/p>\n, Andreas Mezger1<\/sup>, and Markus Rapp1<\/sup>\nAbstract<\/h4>\n
Title: Functional Time Domain Diffuse Correlation Spectroscopy<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/10\/Functional-Time-Domain-Diffuse-Correlation-Spectroscopy-300x175.png\")
Authors: Nisan Ozana1<\/sup>, Niyom Lue2<\/sup>, Marco Renna1<\/sup>, Mitchell B Robinson1,3<\/sup>, Alyssa Martin1<\/sup>, Alexander I Zavriyev1<\/sup>, Bryce Carr1<\/sup>, Dibbyan Mazumder1<\/sup>, Megan H Blackwell2<\/sup>, Maria A Franceschini1<\/sup>, and Stefan A Carp1<\/sup><\/p>\nAbstract<\/h4>\n
Title: Superconducting nanowire single-photon sensing of cerebral blood flow<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/10.1117_1.NPh_.8.3.035006-300x160.png\")
Authors: Nisan Ozana1<\/sup>, Alexander I. Zavriyev1<\/sup>, Dibbyan Mazumder1<\/sup>, Mitchell Robinson1,2<\/sup>, Kutlu Kaya1<\/sup>, Megan Blackwell3<\/sup>, Stefan A. Carp1<\/sup>, and Maria Angela Franceschini1<\/sup><\/p>\nAbstract<\/h4>\n
Aim:<\/strong> To substantially improve SNR, we have built a DCS device that operates at 1064 nm and uses superconducting nanowire single-photon detectors (SNSPD).
Approach:<\/strong> We compared the performances of the SNSPD-DCS in humans with respect to typical DCS system operating at 850 nm and using silicon single-photon avalanche diode detectors.
Results:<\/strong> At a 25-mm separation, we detected 13
Conclusions:<\/strong> While current commercial SNSPDs are expensive, bulky, and loud, they may allow for more robust measures of non-invasive cerebral perfusion in an intensive care setting.<\/p>\nTitle: Noninvasive Optical Monitoring of Cerebral Blood Flow and EEG Spectral Responses after Severe Traumatic Brain Injury: A Case Report<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/10.3390_brainsci11081093-283x300.png\")
Authors: Chien-Sing Poon1<\/sup>, Benjamin Rinehart1<\/sup>, Dharminder S. Langri1<\/sup>, Timothy M. Rambo2<\/sup>, Aaron J. Miller2<\/sup>, Brandon Foreman3<\/sup>, and Ulas Sunar1<\/sup><\/p>\nAbstract<\/h4>\n
where the brain is vulnerable to secondary brain injury. Thus, there is a need for noninvasive, bedside, continuous cerebral blood flow monitoring approaches in the neuro-ICU. Our goal is to address this need through combined measurements of EEG and functional optical spectroscopy (EEG-Optical) instrumentation and analysis to provide a complementary fusion of data about brain activity and function. We utilized the diffuse correlation spectroscopy method for assessing cerebral blood flow at the neuro-ICU in a patient with traumatic brain injury. The present case demonstrates the feasibility of continuous recording of noninvasive cerebral blood flow transients that correlated well with the gold-standard invasive measurements and with the frequency content changes in the EEG data.<\/p>\nTitle: Quantum computational advantage using photons<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/picturepan1-300x126.png\")
<\/p>\nAbstract<\/h4>\n
Title: Detector channel combining results from a high photon efficiency optical communications link test bed<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/10.117_12.2546394-300x257.png\")
Authors: Jennifer N. Downey, Brian E. Vyhnalek, Sarah A. Tedder, and Nicholas C. Lantz<\/p>\nAbstract<\/h4>\n
Title: Generation of broadband correlated photon-pairs in short thin-film lithium-niobate waveguides<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/10.1364_OE.27.038521-300x55.png\")
Authors: Bradley S. Elkus1<\/sup>, Kamal Abdelsalam2<\/sup>, Ashutosh Rao2,3<\/sup>, Vesselin Velev1,4<\/sup>, Sasan Fathpour2<\/sup>, Prem Kumar1<\/sup>, Gregory S. Kanter1<\/sup><\/p>\nAbstract<\/h4>\n
Title: Real Time Photon-Counting Receiver for High Photon Efficiency Optical Communications<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/10.1109_ICSOS45490.2019.8978977-300x160.png\")
Authors: Jennifer N. Downey, Brian E. Vyhnalek, Sarah A. Tedder, and Nicholas C. Lantz<\/p>\nAbstract<\/h4>\n
Title: Decay-Associated Fourier Spectroscopy: Visible to Shortwave Infrared Time-Resolved Photoluminescence Spectra<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/10.1021_acs.jpca_.9b04924-280x300.png\")
<\/p>\nAbstract<\/h4>\n
Title: Few-mode fiber coupled superconducting nanowire single-photon detectors for photon efficient optical communications<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/10.1117_12.2510958-300x245.png\")
<\/p>\nAbstract<\/h4>\n
Title: Experimental rejection of observer-independence in the quantum world<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2022\/01\/10.1126_sciadv.aaw9832-300x81.png\")
<\/p>\nAbstract<\/h4>\n
Title: Attosecond-resolution Hong-Ou-Mandel interferometry<\/h3>\n
![\"\"](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2024\/11\/Attosecond-resolution-Hong-Ou-Mandel-interferometry.png\")
Authors: Ashley Lyons1,2<\/sup>, George C. Knee3<\/sup>, Eliot Bolduc1<\/sup>, Thomas Roger1<\/sup>, Jonathan Leach1<\/sup>, Erik M. Gauger1<\/sup>, and Daniele Faccio1,2<\/sup>.<\/p>\nAbstract<\/h4>\n
Title: Generation of multiphoton entangled quantum states by means of integrated frequency combs<\/h3>\n
![](\"https:\/\/www.quantumopus.com\/web\/wp-content\/uploads\/2017\/01\/Picture1-1.png\")
<\/p>\n
(Website<\/a>)<\/p>\n