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TRANSIA® PLATE Salmonella Gold is an ELISA that was validated by Association Française de Normalisation (AFNOR) in 2001 and as a Performance Tested MethodSM (PTM) by AOAC in 2006 (PTM No. 010602) as a two-step enrichment protocol requiring 48 h. A simple next-day enrichment protocol using modified Enterohemorrhagic Escherichia coli media was developed for the TRANSIA PLATE Salmonella Gold to improve the time-to-results and laboratory work flow. We tested 128 Salmonella strains, representing all serotypes from A though Z and 51–66. TRANSIA PLATE Salmonella Gold detected all 128 of these strains. None of the 50 non-Salmonella strains were detected by TRANSIA PLATE Salmonella Gold. Performance of TRANSIA PLATE Salmonella Gold using the new enrichment protocol was compared with U.S. Department of Agriculture Microbiology Laboratory Guidebook reference culture procedure for the detection of Salmonella in ready-to-eat poultry, ready-to-eat beef, and chicken carcass rinsate. In addition, TRANSIA PLATE Salmonella Gold performance was compared with U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) for the detection of Salmonella from raw spinach, raw almonds, raw pasta, and environmental surfaces (stainless steel, rubber, and plastic). There was no statistically significant difference in the numbers of positive results TRANSIA PLATE Salmonella Gold protocol compared with the appropriate U.S. Department of Agriculture Food Safety and Inspection Service or FDA-BAM reference methods for any of these matrixes. Robustness testing demonstrated that the introduction of small changes in the normal assay parameters had no impact on the method performance. This new enrichment protocol has been approved as a Third Level modification to Performance Tested Method 010602.

Quantum networking brings together several diverse research areas, such as fiber-optic communication, quantum optics, and quantum information, to achieve capabilities in security, secret sharing, and authentication which are unavailable classically. The development of practical fiber-based quantum networks requires an understanding of the reach, rates, and quality of the entanglement of distributed quantum states. Here, we present a theoretical model describing how the magnitude and orientation of polarization dependent loss (PDL), a common impairment in fiber-optic networks, affects the entanglement quality of distributed quantum states. Furthermore, we theoretically characterize how PDL in one fiber channel can be optimally applied in order to nonlocally compensate for the PDL present in another channel. We present experimental results that verify our theoretical model.

Background: The ANSR method is based on isothermal nucleic acid amplification technology. The modifications to assay components improve sensitivity of the assay and robustness of the internal positive control. Objective: A Performance Tested MethodSM validation study was conducted to assess performance of a modified version of the ANSR® for Escherichia coli O157:H7 method. Methods: The validation study included inclusivity/exclusivity, matrix, robustness, accelerated stability, and independent laboratory testing. Results: In inclusivity testing of 55 strains of E. coli O157:H7 and E. coli O157:NM variants, all strains produced positive results. In exclusivity testing of 41 strains including E. coli of other serotypes and bacteria of closely related genera, all strains produced negative results. In matrix testing of beef trim, raw ground beef, spinach, and sprout-irrigation water, ANSR method performance was compared with that of the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook or the U.S. Food and Drug Administration Bacteriological Analytical Manual reference culture procedures. Conclusions: all trials, ANSR method performance was not statistically different from that of the reference methods. Results of independent laboratory testing of ground beef corroborated those of internal testing. Introducing modest changes to three assay operating parameters did not materially affect ANSR method performance. Finally, accelerated stability testing results of three independently manufactured lots of ANSR reagents support a shelf-life of 1 year when stored at 2–8°C.

e16280 Background: Racial disparities in the overall survival (OS) of patients with pancreatic adenocarcinoma (PDAC) have been previously reported. Large population datasets suggest that Non-Hispanic Blacks (NHB) have decreased OS when compared to non-Hispanic Whites (NHW), and Hispanics. It is unclear whether this is related to biologic features or differences in access to care. This study was aimed to compare time to treatment in a racially-diverse cohort of patients with PDAC in an academic center in the Bronx, NY. Methods: Patients diagnosed with PDAC between 2015 and 2021, available race/ethnicity (NHW, NHB or Hispanic) who received treatment at Montefiore Medical Center were identified. Data including demographics (age, gender, BMI), clinical features (date of diagnosis, presentation [localized/metastatic], tumor location, grade), first-treatment received (surgery or chemotherapy) and outcomes (vital status, date of death) were collected manually. Time to first treatment was compared between racial/ethnic groups using the Kruskal-Wallis test. Results: Of 226 patients diagnosed with PDAC, there were 46 (20.4%), 77 (34.1%) and 103 (45.6%) NHW, NHB and Hispanics respectively. The frequency of metastatic disease was higher in Hispanics and NHB compared to NHW (42.7% vs. 46.7% vs. 22.2%, p = 0.02). Median time to first treatment did not differ significantly among racial/ethnic groups in the overall cohort and stratified by disease presentation. Conclusions: There were no differences in access to care among racial/ethnic groups in this cohort. A higher frequency of metastatic disease at presentation among NHB and Hispanics might be explained by more aggressive biology. Further evaluation of the molecular profile in this cohort is warranted.[Table: see text]

Quantum entanglement shared by remote network nodes serves as a valuable resource for promising applications in distributed computing, cryptography, and sensing. However, distributing entanglement with high-quality via fiber optic routes could be challenging due to the various decoherence mechanisms in fibers. In particular, one of the primary polarization decoherence mechanisms in optical fibers is polarization mode dispersion (PMD), which is the distortion of optical pulses by randomly varying birefringences in the system. To mitigate the effect of decoherence in entangled particles, quantum entanglement distillation (QED) algorithms have been proposed. One particular class, the recurrence QED algorithms, stands out because it has relatively relaxed requirements on both the size of the quantum circuits involved and on the initial quality of entanglement in particles. However, because the number of particles required grows exponentially with the number of rounds of distillation, an efficient recurrence algorithm needs to converge quickly. We present a recurrence QED algorithm designed for photonic qubit pairs affected by PMD-degraded channels. Our proposed algorithm achieves the optimal fidelity as well as the optimal success probability (conditional on the optimal fidelity being achieved) in every round of distillation. The attainment of optimal fidelity improves the convergence speed of fidelity with respect to the rounds of distillation from linear to quadratic, and hence significantly reduces the number of distillation rounds. Combined with the fact that the optimal success probability is achieved, the proposed algorithm provides an efficient method to distribute entangled states with high fidelity via optic fibers.

This Conference Presentation, “Polarization-entaglement distribution in fiber-optic channels,” was recorded for the Photonics West 2021 Digital Forum.

In this presentation, we show the efficacy of neural networks in reducing classical resources required for quantum state estimation. The developed methods achieve near-unity fidelities in reconstructed density matrices, and outperform Stokes reconstruction in a wide variety of scenarios.

Quantum networks require robust quantum channels for fast and reliable entanglement distribution over long distances. As quantum communication technology matures, it moves towards utilizing actual fibers and free-space optical channels; hence, there is a growing need for physical models describing decoherence. The primary challenge is to concisely account for numerous elements distributed along a lengthy optical path. We approach this by starting with an analytical model of a channel with just two lumped elements, one representing decoherence and the other representing mode filtering. Interestingly, we find that, while the order and relative orientation of the two elements produce a wealth of different biphoton states, the amount of entanglement in all those states is exactly the same. Then, we conduct experiments that implement this channel and verify our analytical findings. Finally, we expand our analysis to the most general fiber polarization channel, comprising a statistically significant number of arbitrarily oriented elements. We show that, over an ample range of parameters, our two-element analytical model is quite accurate in describing the fiber channel, which makes it an effective tool for gaining insights into channel decoherence.

Polarization entangled photons become partially mixed when transmitted through channels with polarization mode dispersion. We experimentally build a channel that maximizes the amount of mutual quantum information shared between two qubits for a given amount of entanglement left in the two photon system.

We experimentally demonstrate an algorithm to determine the direction of two arbitrarily oriented dephasing elements, one in each of the two quantum channels that are being simultaneously traversed by a two-photon entangled state. Control of the relative orientation of the two elements mitigates the loss of entanglement.

We model the presence of the most general combination of decoherence and mode filtering elements in a quantum channel. We assess the accuracy of using conventional fiber-optic emulators of polarization-mode dispersion and polarization-dependent loss in reproducing the general channel in the laboratory.

A general quantum channel consisting of a decohering and a filtering element carries one qubit of an entangled photon pair. As we apply a local filter to the other qubit, some mutual quantum information between the two qubits is restored depending on the properties of the noise mixed into the signal. We demonstrate a drastic difference between channels with bit-flip and phase-flip noise and further suggest a scheme for maximal recovery of the quantum information.

Future quantum networks offer the potential for new communication and computation applications. These quantum networks will undoubtedly require the routing of quantum information between distant parties. In order to reliably achieve the transmission of entangled states over such a network, some entanglement distillation protocol can be implemented on an ensemble of entangled photon pairs. Here, we demonstrate such a protocol by recovering quantum information using local filters on each photon of a polarization-entangled state in the presence of a common source of decoherence in the telecom fiber infrastructure, polarization mode dispersion (PMD).

We demonstrate robust partially-automated characterization of evanescent coupling between a SNAP microresonator and a tapered optical fiber, and report coupling parameter profiles for two axial series along the taper’s longitudinal axis.

Using a polarization diversity phase modulator, we carry out projective measurements in the spectral domain to characterize frequency-bin entanglement in a hyperentangled photon pair without degrading nonclassical correlations in polarization state.

We report local characterization of coupling between elongated bottle microresonators and tapered-fiber waveguides with small diameter relative to the characteristic length of resonator modes, towards quantum-compatible resonant optical microdevices.

We study the influence of propagation direction on the transmission of polarization entanglement in a channel affected by modal loss and decoherence. We demonstrate symmetric entanglement reduction and asymmetric nonlocal compensation.

We highlight the potential of hyperentangled biphoton frequency combs for quantum communications and networking by implementing frequency-bin quantum operations without degrading entanglement in the polarization degree of freedom.

We present an original non-local ghost measurement scheme with polarization-entangled photons, where nanostructured dielectric metasurfaces enable discrimination between a set of objects with different polarization characteristics, including fully or partially transparent birefringent elements.

Entanglement suffers from noise in quantum channels. Noise originating from bit-flip and phase-flip errors has intrinsically different classical correlations. We find that these can be effectively explored when recovering entanglement by procrustean filtering.

Reconstruction of two-qubit systems typically performed using 36 coincidence measurements. We trained an ensemble of CNN & XGBoost ML models, employed imputation to demonstrate high-fidelity state estimation when multiple measurements are missing.

A protocol of measuring interferometric visibility function using imperfectly entangled states shared between remote telescopes is proposed. We demonstrate how quantum entanglement can be utilized ...

Based on two-photon interference measurements for various pump line-pulse shaper detunings, we show that frequency-bin entanglement can be established in regimes where the pump bandwidth is less than the free spectral range of the biphoton frequency comb.

Polarization dependent loss (PDL) is a serious problem that hinders the transfer of polarization qubits through quantum networks. Recently it has been shown that the detrimental effects of PDL on qubit fidelity can be compensated for with the introduction of an additional passive PDL element that rebalances the polarization modes of the transmitted qubit. This procedure works extremely well when the output of the system is postselected on photon detection. However, in cases where the qubit might be needed for further analysis this procedure introduces unwanted vacuum terms into the state. Here we present procedures for the compensation of the effects of PDL using noiseless amplification and attenuation. Each of these techniques introduces a heralding signal into the correction procedure that significantly reduces the vacuum terms in the final state. When detector inefficiency and dark counts are included in the analysis noiseless amplification remains superior, in terms of the fidelity of the final state, to both noiseless attenuation and passive PDL compensation for detector efficiencies greater than 40%., 8 pages, 6 figures

TRANSIA

Quantum networks entangle remote nodes by distributing quantum states, which inevitably suffer from decoherence while traversing quantum channels. Pertinent decoherence mechanisms govern the reach, quality, and rate of distributed entanglement. Hence recognizing, understanding, and modeling those mechanisms is a crucial step in building quantum networks. Here, we study real-life fiber-optic quantum channels that partially filter individual modes of transmitted polarization-entangled states and are capable of introducing dephasing. First, we theoretically model and experimentally demonstrate the combined effect of two independent and arbitrarily oriented polarization-dependent loss elements experienced by each photon of an entangled photon pair. Then, we showcase the compensation of lost entanglement by properly adjusting the channels’ properties and discuss the resulting tradeoff between the entanglement quality and rate. Our results provide insights into the robustness of fiber-optic quantum channels, thus taking an important step toward the realization of quantum networks. If one photon in an entangled pair suffers from losses common to optical fibers, it can be compensated for by using just the other photon. As quantum communication technologies approach practical applications, greater attention is being paid to issues that affect realistic devices rather than theoretical idealisations. To construct a quantum network, entanglement has to be shared between distant nodes, which is often achieved by sending entangled photon pairs to the nodes using optical cables. Daniel Jones and colleagues from the U.S. Army Research Laboratory have analysed how entangled photons are affected by polarization-dependent losses that arise in fiber optic cables due to residual imperfections and changes in their environment. They show that reductions in entanglement quality caused by losses affecting one photon can be non-locally recovered by adjusting the other photon’s propagation.

Coupling between optical microresonators and waveguides is a critical characteristic of resonant photonic devices with complex behavior that is not well understood. When the characteristic variation length of the microresonator modes is much larger than the waveguide width, local coupling parameters emerge that are independent of the resonator mode distributions and offer a simplified description of coupling behavior. We develop a robust numerical-fitting-based methodology for experimental determination of the local coupling parameters in all coupling regimes and demonstrate their characterization along a microfiber waveguide coupled to an elongated bottle microresonator., 7 pages and 3 figures. Version 3 is substantially revised and reformatted

We build a general quantum state tomography framework that makes use of machine learning techniques to reconstruct quantum states from a given set of coincidence measurements. For a wide range of pure and mixed input states we demonstrate via simulations that our method produces functionally equivalent reconstructed states to that of traditional methods with the added benefit that expensive computations are front-loaded with our system. Further, by training our system with measurement results that include simulated noise sources we are able to demonstrate a significantly enhanced average fidelity when compared to typical reconstruction methods. These enhancements in average fidelity are also shown to persist when we consider state reconstruction from partial tomography data where several measurements are missing. We anticipate that the present results combining the fields of machine intelligence and quantum state estimation will greatly improve and speed up tomography-based quantum experiments., 8 pages

The TRANSIA

We experimentally investigate the entanglement quality of polarization-entangled photon pairs transmitted through two fibers with PDL. We compensate for entanglement loss due to PDL despite the presence of significant PMD. A theory supports our observations and provides insight into the conditions necessary for complete compensation.

We present a novel method based on optical fibre tapering for fabrication of Surface Nanoscale Axial Photonics (SNAP) devices with parabolic profiles with an unprecedentedly large number of axial eigenmodes. Tapering of a commercial 125 μm single-mode optical fibre to a 30 μm diameter waist by laser brushing creates a SNAP bottle microresonator with parabolic radius variation in the centre of the tapered region. Ideal parabolic resonators should demonstrate equal spacing between resonances. Our spectral measurement of the parabolic profile shows spacing of ∼6 GHz with 10% deviation over a bandwidth of 2.5 THz containing up to 400 axial eigenfrequencies. This new discovery for the creation of SNAP parabolic microresonator devices is important for fabrication of miniature delay lines, buffers and frequency comb generators. Characterisation of our exemplar microresonators is briefly explored, particularly for broadband frequency comb generators which require equidistant frequency spacing. Further investigations include scaling of the parabolic feature with tapering process parameters, repeatability testing, and the fabrication of more complex shapes.