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Purpose:Myelodysplastic syndrome (MDS) is associated with a dysregulated innate immune system. The purpose of this study was to determine whether modulation of the innate immune system via high mobility group box-1 (HMGB1) could reduce cell viability in MDS.Experimental Design:We quantified HMGB1 in an MDS cell line MDS-L and in primary MDS cells compared with nonmalignant hematopoietic cells. We performed loss-of-function studies of HMGB1 using pooled siRNAs and a small-molecule inhibitor sivelestat compared with standard chemotherapy. We measured levels of engraftment of MDS-L cells in NOD-scidIL2Rgnull (NSG) mice following treatment with sivelestat. Mechanistically, we interrogated cell survival pathways and 45 targets within the NFκB pathway using both protein analysis and a proteome profiler array.Results:We discovered that HMGB1 had increased expression in both MDS-L cells and in primary CD34+ MDS cells compared with healthy CD34+ hematopoietic cells. Sivelestat impaired MDS cell expansion, increased cellular death, and spared healthy hematopoietic cells. MDS-L marrow engraftment is reduced significantly at 17 weeks following treatment with sivelestat compared with control mice. Treatment of CD34+ MDS cells with sivelestat and azacitidine or decitabine was additive to increase apoptotic cell death compared with chemotherapy alone. Sivelestat promoted apoptosis with increased expression of PUMA, activated caspase 3, and increased DNA double-strand breaks. Inhibition of HMGB1 reduced levels of Toll-like receptors (TLR) and suppressed activation of NFκB in MDS-L cells.Conclusions:Inhibition of HMGB1 could promote MDS cell death and alter innate immune responses via suppression of NFκB pathways.

The association of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) status before delivery with breastfeeding is unknown. This study compares breastfeeding initiation, exclusivity, and duration between SARS-CoV-2-positive (+) and SARS-CoV-2-negative (-) mothers during the first 2 months of their newborns' lives.A single center, retrospective cohort study of pediatric contacts during the first 2 months in a diverse mother-infant population (n = 285) compared breastfeeding outcomes by maternal SARS-CoV-2 status during a pandemic surge. Infants of SARS-CoV-2 positive mothers were also tested before discharge. Comparison of maternal demographics (age, race, ethnicity), maternal/infant characteristics (parity, insurance, delivery mode, infant sex, hospital length of stay), and pediatric contacts by maternal SARS-CoV-2 status included Fisher's exact and Wilcoxon tests and Poisson regression for count outcomes. Logistic regression compared breastfeeding outcomes between the 2 groups, adjusting for potential confounders and effect modifiers.Maternal demographics and maternal/infant characteristics were similar. While 19% of mothers tested positive for SARS-CoV-2 (n = 54), their infants were all negative. SARS-CoV-2 positive mothers had fewer in-person, but more virtual pediatric contacts. After controlling for the above variables, SARS-CoV-2 positive mothers had lower odds of breastfeeding initiation within 1 to 7 days of life (78% vs 88%; adjusted odds ratio [aOR] = 0.40, 95% confidence interval [CI]: 0.17, 0.96) and of any breastfeeding during month 2 (54% vs 76%; aOR = 0.37, 95% CI: 0.16, 0.86) compared with SARS-CoV-2 negative mothers.Maternal SARS-CoV-2 positivity at delivery was independently associated with less initiation and shorter duration of any breastfeeding during month 2. SARS-CoV-2 positive women would likely benefit from additional breastfeeding support during pandemic surges.

Purpose: Myelodysplastic syndrome (MDS) is associated with a dysregulated innate immune system. The purpose of this study was to determine whether modulation of the innate immune system via high mobility group box-1 (HMGB1) could reduce cell viability in MDS. Experimental Design: We quantified HMGB1 in an MDS cell line MDS-L and in primary MDS cells compared with nonmalignant hematopoietic cells. We performed loss-of-function studies of HMGB1 using pooled siRNAs and a small-molecule inhibitor sivelestat compared with standard chemotherapy. We measured levels of engraftment of MDS-L cells in NOD-scidIL2Rgnull (NSG) mice following treatment with sivelestat. Mechanistically, we interrogated cell survival pathways and 45 targets within the NFκB pathway using both protein analysis and a proteome profiler array. Results: We discovered that HMGB1 had increased expression in both MDS-L cells and in primary CD34+ MDS cells compared with healthy CD34+ hematopoietic cells. Sivelestat impaired MDS cell expansion, increased cellular death, and spared healthy hematopoietic cells. MDS-L marrow engraftment is reduced significantly at 17 weeks following treatment with sivelestat compared with control mice. Treatment of CD34+ MDS cells with sivelestat and azacitidine or decitabine was additive to increase apoptotic cell death compared with chemotherapy alone. Sivelestat promoted apoptosis with increased expression of PUMA, activated caspase 3, and increased DNA double-strand breaks. Inhibition of HMGB1 reduced levels of Toll-like receptors (TLR) and suppressed activation of NFκB in MDS-L cells. Conclusions: Inhibition of HMGB1 could promote MDS cell death and alter innate immune responses via suppression of NFκB pathways.

A novel machine-learning algorithm based on single-shot measurements, named single-shot measurement learning, is demonstrated achieving the theoretical optimal accuracy. The method is at least as efficient as existing tomographic schemes and computationally much less demanding. The merits are attributed to the inclusion of weighted randomness in the learning rule governing the exploration of diverse learning routes. These advantages are explored experimentally by a linear-optical setup that is designed to draw the fullest potential of the proposed method. The experimental results show an unprecedented high level of accuracy for qubit-state learning and reproduction exhibiting (nearly) optimal infidelity scaling, O(N^{-0.983}), for the number N of unknown state copies, down to

High-efficiency and wavelength-selective excitation of higher-order cladding modes in a four-core fiber is implemented using an acousto-optic mode converter. Dynamic inter-core routing through core-to-cladding-to-core three-mode coherent coupling is demonstrated with good agreement with theory.

Vaccines are one of the greatest public health achievements, protecting children and adults against numerous infectious diseases; however, the complex, rigorous process of vaccine development is unknown to many. A candidate vaccine undergoes extensive evaluation of safety and efficacy to meet licensure requirements before recommendations for use become policy. This time-consuming process involves an intricate collaboration among academia, public and private organizations, and federal agencies to ensure that safety is prioritized in every step. Vaccine safety continues to be monitored after licensure through a robust system. Yet, vaccine hesitancy remains a major challenge, especially now with the coronavirus disease 2019 (COVID-19) pandemic and concerns about the speed with which candidate vaccines are being developed. This article reviews the vaccine development process and the systems in place to ensure safety and effectiveness. A better understanding of these topics is necessary to address concerns and improve public acceptance of all vaccines, particularly COVID-19 vaccines. [ Pediatr Ann . 2020;49(12):e509–e515.]

Background Effortful swallowing training (EST) is a remedial method for the training of swallowing-related muscles in the oropharyngeal phase. However, clinical evidence of its effectiveness is insufficient. Aims To investigate the effects of EST on tongue strength and swallowing function in patients with stroke. Methods & procedures Stroke patients with dysphagia were randomly assigned to one of two groups: an experimental group (n = 12) and a control group (n = 12). The experimental group underwent EST, while the control group performed saliva swallowing. Training was conducted 5 days per week for 4 weeks. Both groups underwent conventional dysphagia treatment for 30 min/day, 5 days/week for 4 weeks. Outcomes & results Tongue strength was assessed using the Iowa Oral Performance Instrument. The Videofluoroscopic Dysphagia Scale (VDS), based on a videofluoroscopic swallowing study, was used to analyze oropharyngeal swallowing function. The experimental group showed greater improvements in anterior and posterior tongue strength compared with the control group (p = 0.046 and 0.042, respectively), and greater improvement in the oral phases of the VDS (p = 0.017). Conclusions & implications We recommend EST as a remedial strategy for improving tongue strength and oral swallowing function in patients with stroke.

We demonstrate an acousto-optic mode converter based on a tapered optical fiber to efficiently generate orbital angular momentum states of light. In our scheme an acoustic wave is deployed to the waist of tapered optical fiber where two degenerate HE21 modes leading to +1 and −1 orbital angular momentum eigen-modes are resonantly excited. The excitation of TM01 and TE01 modes is suppressed by enlarging the intermodal index difference between near-degenerate spatial modes. Numerical calculation for optimization of the taper diameter is provided. The experimental characterization of generated states is performed by analyzing the output far-field pattern and the spatial interference fringes with a uniform reference beam.

This letter presents an experimental method to compensate for the differential group delay between the core modes in a multi-core fiber. Optical fiber sections are sequentially spliced with azimuthal offsets such that light initially launched to any cores can propagate through the combination of the same lengths of different cores, resulting in ideally uniform group delay. The differential group delays before and after the compensation are measured by wavelength-domain Mach–Zehnder interferometry through multi-core fiber sections. The experimental results show that the group delay compensation is practically limited by non-uniformity of the multi-core fiber.

We demonstrate time-multiplexing of heralded single-photon sources using switchable optical fiber d elay l ines a ided b y p olarization-space m ultiplexing. Relative-multiplexing HOM interferometry tests the indistinguishability of output photons.

We report the measurement of bending-induced birefringence in the presence of large intrinsic birefringence in a hollow-core photonic crystal fiber (HC-PCF). The fast axis of bending-induced birefringence was found to be normal to the bending plane, in contrast to the conventional fiber case. The dependence of the induced birefringence on the bending radius was also different from the typical inverse square law. Possibilities and design criteria for polarization controllers using bending-induced birefringence in HC-PCFs are presented.

Quantum teleportation allows to transfer unknown quantum states between distant parties. It is not only a primitive of quantum communications but also an essential task in realization of the quantum networks for promising applications such as quantum cryptography and distributed quantum computation. Despite recent substantial progresses in the realization of quantum communications, teleportation of shared quantum information between multiple senders and receivers is still missing. Here we propose and experimentally demonstrate quantum teleportation among spatially separate parties in a quantum network. The protocol can be jointly performed by distributed participants, while none of them can fully access the transferred information. It can be generally extended to quantum communications incorporating an arbitrary number of parties without a trusted central node. Our work opens a route to the realization of distributed quantum communications and computations in quantum networks

We experimentally demonstrate a time-multiplexing method for pulse-pumped heralded single-photon sources using switchable optical fiber delay lines. The optical fibers constitute a 32-channel binary-division photon buffer that can multiplex time slots into single temporal mode to enhance single-photon generation rate without increasing multi-photon noise. Relative time multiplexing using the same actively controlled variable delay realizes Hong-Ou-Mandel interferometry by two photons produced in arbitrary two time-bins. The interference dip depth in good agreement with theory verifies path length matching within the photonic coherence length and dispersion compensation of the optical fiber delay sections. We independently confirm by low-coherence interferometry that the internal optical path lengths of the optical switches are constant during the switching operations.

Plasma neutrophil gelatinase-associated lipocalin (NGAL) is a useful biomarker for predicting acute kidney injury (AKI). The purpose of this study was to evaluate the diagnostic performance of urinary NGAL in predicting AKI in sepsis patients in the emergency department.A total of 140 patients were enrolled. We compared serum procalcitonin and urinary NGAL concentrations between patients with local infection, sepsis, and septic shock, and between patients who did and did not develop AKI with sepsis. Receiver-operating characteristic curve analysis was used to evaluate the ability to predict AKI in sepsis patients.Both serum procalcitonin and urinary NGAL concentrations were significantly higher in the sepsis and septic shock groups than in the local infection group (both p 0.001). In sepsis patients, serum procalcitonin and urinary NGAL concentrations were higher in AKI patients than in those without AKI (p = 0.006, p 0.001, respectively). The area under the curve for predicting of AKI was higher for a urinary NGAL of 0.820 (95% confidence interval (CI) 0.721-0.895) than for a serum procalcitonin concentration of 0.76 (95% CI 0.597-0.800).Urinary NGAL concentration may predict AKI in patients with sepsis in the emergency department.

We calculate optical properties of guided modes of a hybrid-guiding photonic crystal fiber. The design and modeling of such hybrid-guiding PCF is made by replacing air holes with inserts of high refractive index material layer by layer in order. The optical properties such as mode intensity profile, mode dispersion, optical birefringence, confinement loss, and chromatic dispersion during transition of the guiding mechanism are analyzed and discussed. The guided modes in the hybrid-guiding region are also compared with those of reference index-guiding and bandgap-guiding photonic crystal fibers.

We calculate the operation wavelength range of polarization controllers based on rotating wave plates such as paddle-type optical fiber devices. The coverages over arbitrary polarization conversion or arbitrary birefringence compensation are numerically estimated. The results present the acceptable phase retardation range of polarization controllers composed of two quarter-wave plates or a quarter-half-quarter-wave plate combination, and thereby determines the operation wavelength range of a given design. We further prove that a quarter-quarter-half-wave-plate combination is also an arbitrary birefringence compensator as well as a conventional quarter-half-quarter-wave-plate combination, and show that the two configurations have the identical range of acceptable phase retardance within the uncertainty of our numerical method.

Anterior and posterior intervertebral gap of lumbar spine is important when developing the spinal implants regarding lumbar system. However, the measuring methods continue to be still controversial because of the absence of a standardized measurement. The objective of this study is to propose novel methods of measuring lumbar intervertebral gap and to conduct comparative analysis with other measuring methods. We took the lateral radiography images of 20 males taking the postures of supine, seat and standup. The anterior intervertebral gap and posterior intervertebral gap were measured with three different methods and two pre-existing methods. The comparison of results from three different measuring methods and two pre-existing methods showed that the difference at the anterior intervertebral gap was mostly statistically significant. This study suggests that it is necessary to consider the clinical meaning of the difference among measuring methods in order to establish a database to fabricate spine implants and to make efforts to improve measuring methods in the future.

We present a practical calibration method of the detection efficiency (DE) of single photon detectors (SPDs) in a wide wavelength range from 480 nm to 840 nm. The setup consists of a GaN laser diode emitting a broadband luminescence, a tunable bandpass filter, a beam splitter, and a switched integrating amplifier which can measure the photocurrent down to the 100 fA level. The SPD under test with a fibre-coupled beam input is directly compared with a reference photodiode without using any calibrated attenuator. The relative standard uncertainty of the DE of the SPD is evaluated to be from 0.8% to 2.2% varying with wavelength (k = 1).

177 Copyrightc 2016 The Korean Association of Internal Medicine This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Received: 2015. 8. 24 Revised: 2015. 9. 10 Accepted: 2015. 9. 16

In this paper, we propose a deterministic secure quantum communication (DSQC) protocol based on the BB84 system. We developed this protocol to include quantum entity authentication in the DSQC procedure. By first performing quantum entity authentication, it was possible to prevent third-party intervention. We demonstrate the security of the proposed protocol against the intercept-and-re-send attack and the entanglement-and-measure attack. Implementation of this protocol was demonstrated for quantum channels of various lengths. Especially, we propose the use of the multiple generation and shuffling method to prevent a loss of message in the experiment.

We propose a schematic setup of quantum key distribution (QKD) with an improved secret key rate based on high-dimensional quantum states. Two degrees-of-freedom of a single photon, orbital angular momentum modes, and multi-path modes, are used to encode secret key information. Its practical implementation consists of optical elements that are within the reach of current technologies such as a multiport interferometer. We show that the proposed feasible protocol has improved the secret key rate with much sophistication compared to the previous 2-dimensional protocol known as the detector-device-independent QKD., Comment: 10 pages, 6 figures

In this study, a cotton knit was dyed with elm bark extract; subsequently, the dyed fabric was measured according to the types of mordants and the preprocessing cationizers used. Additionally, antibiosis against super bacteria was examined. The results follow. First, the color of the dyed cotton knit appeared reddish and yellowish for fabrics treated with non-mordants and mordants. When preprocessing with a cationizer was conducted, the dyeing properties were the best. Second. even when mordants were not used for dyeing, color fastness after washing, sweating, and rubbing was generally good Grade 4 and 5. Color fastness after exposure to sunlight was the best Grade 4 for fabric prepared with ferrous sulfate as the mordant. Third. as for antimicrobial properties, or resistance to super bacteria, the growth of bacteria was suppressed in a meaningful way for fabrics treated with non-mordants and mordants, compared to the control group fabric. The dyeing methods with the most powerful antimicrobial effects were dyeing after preprocessing with a cationizer and preparing fabric with copper sulfate as the mordant. The results stated above show that in case of dyeing with elm bark extract, preprocessing of the cotton knit with a cationizer and dying with copper mordant displayed high levels of antimicrobial properties that were useful for resisting super bacteria. Of these the dyeing properties were the best when preprocessing with a cationizer.

We demonstrate a highly efficient acoustooptic mode converter for selective excitation of the higher-order modes in a four-mode fiber which guides the LP01, LP11, LP21, and LP02 modes at telecommunication wavelengths. The coupling efficiency and the mode extinction ratio are measured by analyzing the output far-field patterns. The acoustic resonance frequencies and the operating bandwidths are compared with the theoretical results, by which the modal characteristics, the core diameter, and the core-cladding index difference are estimated.

[Purpose] The purpose of this study was to compare the strength and endurance of the orbicularis oris muscle in healthy Korean (young vs. elderly adults). [Participants and Methods] A total of 60 participants (30 young adults and 30 elderly adults) were recruited. The Iowa Oral Performance Instrument was used to measure orbicularis oris muscle maximal strength and endurance. [Results] Elderly adults showed significantly lower orbicularis oris muscle strength and endurance than younger adults. [Conclusion] This study confirmed a significant age-related decrease in orbicularis oris muscle strength and endurance. The data collected will be useful as a basis for future on speech and swallowing therapy.

We demonstrate the measurement of detection efficiency, the probability for the successful detection of a single photon incident on a detector, in a wide wavelength range from 250 nm to 1000 nm. The method is based on the responsivity comparison of two detectors by using a tunable monochromatic light source at a radiant power controlled to the pico-Watt level. As the reference detector, a photodiode with a switched integrating amplifier is used, whose spectral responsivity is calibrated at a photo-current level of pico-Ampere. A fibre-based spatial filter is used to form a beam focus that is focused to a diameter of less than 100 µm at the detector under test. The typical uncertainty of the detection-efficiency measurement for a Si-based single photon avalanche photodiode is evaluated to be less than 1% as a relative standard uncertainty (k = 1), which is currently limited by the characteristics of the tunable source.

Oxylipins are known to have several biological functions. The oxylipin 7,10-dihydroxy-8(E)-octadecenoic acid (DOD), produced from oleic acid by Pseudomonas aeruginosa, was reported to have strong antibacterial activities against broad range of food-borne and plant pathogenic bacteria. Among DOD producers, P. aeruginosa PR3 shows efficient production of DOD from oleic acid, triolein, and olive oil. In this study, we report the serendipitous isolation and characterization of a variant strain of PR3, which upon examination showed higher efficiency for DOD production from olive oil than the original PR3 strain. Compared with the PR3 strain, the variant strain displayed enhanced DOD production by 47.6% and different carbon requirements for maximum DOD production. Considering the advantageous differences seen in this study, we propose the further characterization of this new strain and optimization of culture conditions for efficient DOD production.

We demonstrate an experimental method to control four-dimensional spatially entangled states between two multi-core optical fibers based on spatial beam shaping of a laser that pumps spontaneous parametric down-conversion.

A 48-year-old woman was referred to our clinic because she had been experiencing hemoptysis for 1 month. Chest computed tomography revealed a small portion of a thyroid mass was penetrating the trachea. Bronchoscopy revealed a blood vessel covered mass located in her trachea. The presence of a malignant tumor was confirmed by a biopsy. The patient was referred to the otolaryngology department for tumor resection and a pathological evaluation identified the thyroid angiosarcoma with tracheal invasion. Angiosarcomas have a poor prognosis, but the patient has not experienced any recurrence two years after surgery. A very rare case of primary thyroid angiosarcoma with tracheal invasion was cured successfully.

[Purpose] We aimed to investigate the effect of resistance training of the orbicularis oris muscles on lip muscle strength and closure function in patients with swallowing disorder with facial palsy after stroke. [Participants and Methods] This study recruited 10 patients with swallowing disorder and facial palsy after stroke. All the participants received orbicularis oris muscle training at an intensity of 70% of 1 repetition maximum by using an Iowa oral performance instrument. Muscle strength and lip closure function were evaluated after orbicularis oris muscle training. [Results] After the intervention, the orbicularis oris muscle strength showed a statistically significant increase from 20.5 ± 5.15 to 25.3 ± 4.2 kilopascal. Lip closure function showed a statistically significant improvement from 2.6 ± 1.5 to 1.2 ± 1.0. [Conclusion] This study recommends to train at an intensity of 70% of 1 repetition maximum for 4 weeks to increase theorbicularis oris muscle strength and improve lip closure function.

Nanoimprint lithography has been widely used in various applications as a promising micro/nanofabrication tool. In the thermal nanoimprint process, optimization of important process parameters such as temperature, pressure, and pressure holding time is greatly needed to successfully imprint micro-and nanoscale patterns in a resist material. In this study, both experimentation and numerical simulation were performed to extend the understanding of the behaviour of polymer materials and to optimize process condition effectively during the thermal imprint process. The effects of the process conditions on the polymer deformation are discussed to achieve a rapid and high throughput thermal imprint process.

We propose a linear optical scheme that can conditionally generate high NOON states using polarization modes. This scheme provides advantages over the previous proposals on path-entangled NOON states in view of success probability or required resources of optical elements. We also investigate two experimental schemes feasible within existing technology that can produce the NOON-like or the NOON state for N = 4., Published version, 5 pages, 4 figures

High-dimensional entanglement is a valuable resource for secure and efficient quantum information processing. A major challenge for practical use of multidimensional quantum systems is the establishment of controls over arbitrary superposition states in realistic conditions. This work demonstrates spatially entangled photon pairs propagating through two separate four-core optical fibers with the amplitudes and phases of the superposition being independently controllable. Using quantum state analyzers that can detect arbitrary multicore superposition states, Bell-type CGLMP inequalities in two, three, and four dimensions are directly tested. Enhanced violation of the inequality by slight nonmaximality of entanglement is also demonstrated.

Myelodysplastic syndrome (MDS) is a heterogeneous and pre-leukemic clonal stem cell disorder characterized by aberrant hematopoiesis and bone marrow failure. Since MDS is associated with a dysregulated innate immune system, we performed a genetic screen of the human toll-like receptor (TLR) pathway and found that high mobility group box-1 (HMGB1) was abundantly expressed in MDS. HMGB1 is a ubiquitously expressed, non-histone chromatin-binding protein. In solid cancers, high expression of HMGB1 was associated with both shortened progression-free and overall survival, but its role in hematologic malignancies is not well defined. We hypothesized that targeting HMGB1 could be therapeutic in MDS. To study HMGB1 in human MDS, we utilized a cell line, MDS-L, derived from a patient with myelodysplastic syndrome with ring sideroblasts. Morphologically, the cells display dysplastic features, including cytoplasmic vacuolation and prominent, irregular nucleoli. We found that HMGB1 was detected at high levels in both MDS-L and in primary CD34+ MDS compared to CD34+ cord blood and healthy human marrow (*p Next, we sought to pharmacologically inhibit HMGB1 signaling with sivelestat, which is a small molecule inhibitor for neutrophil elastase and HMGB1. Since sivelestat has not been studied in either normal or malignant hematopoiesis, whether it or other HMGB1 inhibitors could impact MDS is not yet defined. Following 72 h culture, HMGB1 protein levels were decreased in both MDS-L cells and in primary CD34+ MDS cells treated with 300 mg/ml sivelestat compared to cultures with vehicle alone (*p Since treatment with sivelestat could decrease both MDS cell expansion and impair the ability to generate colonies in methylcellulose assays, we sought to determine whether blocking HMGB1 could decrease MDS engraftment in NOD-scid ILR2gnull (NSG) mice. At 17 weeks, irradiated NSG mice that were transplanted with MDS-L cells treated with sivelestat demonstrated a 3.2-fold decrease in human CD45 marrow engraftment with MDS-L compared to control cultures (*p Mechanistically, sivelestat increased cellular apoptosis in cultures of MDS cells compared to control cultures (*p=0.001). This was done in part by increasing levels of p53 upregulated modulator of apoptosis (PUMA, *p=0.0003), activated caspase 3 (*p Disclosures No relevant conflicts of interest to declare.

We describe two methods for evaluating the dead time of a time-to-amplitude converter (TAC). The dead time is obtained by measuring either the corresponding time interval in an oscilloscope trace or the relation between the single count rate and the coincidence count rate. Values for the TAC dead time are obtained in the range from 3.4 µs to 14.3 µs for the two methods with respective standard uncertainties of 2.9 × 10−8 s and 3.3 × 10−9 s. The TAC dead time is applied to the calibration of coincidence-counting measurements of optical transmission and photon-heralding efficiency.

We propose and demonstrate an experimental technique that generates and measures arbitrary superpositions of the core modes in a multi-core fiber. This technique is potentially useful for transmission of high-dimensional quantum states through optical fiber.

Photons have proven to be excellent carriers of quantum information and play essential roles in numerous quantum information processing (QIP) applications. In particular, heralded single-photon sources via spontaneous parametric-down conversion (SPDC) have been a key technology for demonstrating small-scale QIP, yet their low generation efficiency is a critical limitation to furthering the scale-up of optical QIP technology. In order to efficiently overcome the probabilistic nature of SPDC, here we demonstrate time multiplexing for up to 30 time slots of a periodically pumped heralded single-photon source using a switchable low-loss optical storage cavity. We observe a maximum single-photon probability of 38.6±0.4% in periodic output time windows, corresponding to ∼6 times enhancement over a nonmultiplexed source but with no increase in the contribution of unwanted multiphoton events. Combining this time-multiplexing technique with a heralded source producing pure single-photon states should enable larger-scale optical QIP systems than previously realized.

We demonstrate an experimental technique to generate and measure arbitrary superpositions of core modes in a multi-core fiber. Two spatial light modulators couple the fundamental mode of a single-mode fiber with multiple-core modes of the MCF to constitute a Mach-Zehnder-type multi-path interferometer. The phase tunability of each path is verified by comparing two-, three-, and four-path interference patterns with the theory. Interference fringes in the wavelength domain estimates the inter-core group index differences with a resolution of 10(-5) using a fiber length of 1 m.

This paper describes a novel non-contact laser-ultrasound system which is compact and has a high level of immunity to ambient vibration, based on the use of an optical fibre Fabry–Perot interferometer as an acoustic detector. The new optical acoustic detector was employed for measuring a high-frequency acoustic wave of small amplitude generated by a relatively low output power source using an erbium-doped fibre amplifier. Together with the characteristics of the proposed detector, the preliminary results of 80 MHz laser-ultrasound experiments on an aluminium film are described.