Bright squeezed vacuum in a nonlinear interferometer: frequency/temporal Schmidt-mode description

Control over the spectral properties of the bright squeezed vacuum (BSV), a highly multimode non-classical macroscopic state of light that can be generated through high-gain parametric down conversion, is crucial for many applications. In particular, in several recent experiments BSV is generated in a strongly pumped SU(1,1) interferometer to achieve phase supersensitivity, perform broadband homodyne detection, or tailor the frequency spectrum of squeezed light. In this work, we present an analytical approach to the theoretical description of BSV in the frequency domain based on the Bloch-Messiah reduction and the Schmidt-mode formalism. As a special case we consider a strongly pumped SU(1,1) interferometer. We show that different moments of the radiation at its output depend on the phase, dispersion and the parametric gain in a nontrivial way, thereby providing additional insights on the capabilities of nonlinear interferometers. In particular, a dramatic change in the spectrum occurs as the parametric gain increases

Properties of bright squeezed vacuum at increasing brightness

A bright squeezed vacuum (BSV) is a nonclassical macroscopic state of light, which is generated through high-gain parametric down-conversion or four-wave mixing. Although the BSV is an important tool in quantum optics and has a lot of applications, its theoretical description is still not complete. In particular, the existing description in terms of Schmidt modes with gain-independent shapes fails to explain the spectral broadening observed in the experiment as the mean number of photons increases. Meanwhile, the semiclassical description accounting for the broadening does not allow us to decouple the intermodal photon-number correlations. In this work, we present a new generalized theoretical approach to describe the spatial properties of a multimode BSV. In the multimode case, one has to take into account the complicated interplay between all involved modes: each plane-wave mode interacts with all other modes, which complicates the problem significantly. The developed approach is based on exchanging the (k, t ) and (ω, z) representations and solving a system of integrodifferential equations. Our approach predicts correctly the dynamics of the Schmidt modes and the broadening of the angular distribution with the increase in the BSV mean photon number due to a stronger pumping. Moreover, the model correctly describes various properties of a widely used experimental configuration with two crystals and an air gap between them, namely, an SU(1,1) interferometer. In particular, it predicts the narrowing of the intensity distribution, the reduction and shift of the side lobes, and the decline in the interference visibility as the mean photon number increases due to stronger pumping. The presented experimental results confirm the validity of the new approach. The model can be easily extended to the case of the frequency spectrum, frequency Schmidt modes, and other experimental configurations

Projective filtering of a single spatial radiation eigenmode

Lossless filtering of a single coherent (Schmidt) mode from spatially multimode radiation is a problem crucial for optics in general and for quantum optics in particular. It becomes especially important in the case of nonclassical light that is fragile to optical losses. An example is bright squeezed vacuum generated via high-gain parametric down conversion or four-wave mixing. Its highly multiphoton and multimode structure offers a huge increase in the information capacity provided that each mode can be addressed separately. However, the nonclassical signature of bright squeezed vacuum, photon-number correlations, are highly susceptible to losses. Here we demonstrate lossless filtering of a single spatial Schmidt mode by projecting the spatial spectrum of bright squeezed vacuum on the eigenmode of a single-mode fiber. Moreover, we show that the first Schmidt mode can be captured by simply maximizing the fiber-coupled intensity. Importantly, the projection operation does not affect the targeted mode and leaves it usable for further applications.Comment: 10 pages, 9 figure

ЩОДО ПИТАННЯ УПРАВЛІННЯ ТА ОЦІНЮВАННЯ РИЗИКІВ У ДІЯЛЬНОСТІ СУДОВО-ЕКСПЕРТНИХ УСТАНОВ УКРАЇНИ

The use of international standard ISO / IEC 17025 in forensic institutions of Ukraine is an integral part of the international recognition procedure of the tests (examinations) results that they conduct. In connection with the entry of a new version of the international standard ISO / IEC 17025: 2017 and DSTU ISO / IEC 17025: 2017 into legal force, the issues of meeting new standards requirements have become increasingly relevant. The international standard provides for the use of risk-based thinking and a process approach in any field of activity, including forensic science. When conducting research, practitioners are faced with internal and external factors and various influences that lead to uncertainties in the degree of confidence regarding the examination result. Institutions that will evaluate and manage risks during their activity will have an advantage over other forensic institutions.   The purpose of the article is to review approaches to risk management and assessment, to suggest creating a single documented procedure for the risk management procedure in testing laboratories in the field of forensic science.   The article considers the concepts, basic approaches to risk management and assessment, as well as the authors present the risk management procedure developed by them in the testing laboratory of a forensic institution, which includes the stages of risk management and a risk assessment matrix.   Despite the fact that ISO / IEC 17025: 2017 does not require the development of a documented procedure for risk management, we nevertheless believe that it should be introduced for the effective operation of the testing laboratory. Development of a unified management procedure for managing and accessing risks in forensic activities will increase the results reliability of these activities.Застосування в судово-експертних установах України Міжнародного стандарту ISO/IEC 17025 є невід’ємною складовою процедури міжнарод-ного визнання результатів випробувань (досліджень), які вони проводять. Стандарт передбачає використання ризик-орієнтованого мислення та процесного підходу в будь-якій сфері діяльності, зокрема і в судово-екс-пертній. Розробляння єдиної процедури менеджменту щодо управління оцінювання ризиків у судово-експертній діяльності дасть змогу підвищи-ти достовірність результатів цієї діяльності.   Метою статті є огляд підходів до управління та оцінювання ризиків, пропозиція створення єдиної задокументованої процедури ризик-мене­ джменту випробувальних лабораторій у галузі судово-експертної діяль-ності

Novel LRBA Mutation and Possible Germinal Mosaicism in a Slavic Family

Peer reviewe

Influence of chronic opisthorchiasis on virologic response in patients with chronic hepatitis С during standard antiviral treatment

In order to assess the impact of chronic opisthorchiasis on virologic response in patients with chronic hepatitis С were examined 24 patients with chronic hepatitis С in combination with opisthorchiasis (study group) and 24 patients with chronic hepatitis С without opisthorchiasis (control group). All patients received standard antiviral therapy of IFN-a and ribavirin for 24 weeks. Viral load was assessed at 4,12 and 24 weeks of treatment. In result, there is no negative influence of chronic opisthorchiasis on virologic response in patients with chronic hepatitis С during 24 weeks of antiviral treatment.С целью изучения влияния хронической описторхозной инвазии на характер вирусологического ответа у больных хроническим гепатитом С было обследовано 24 пациента с хроническим гепатитом С в сочетании с описторхозом (опытная группа) и 24 больных хроническим гепатитом С без описторхоза (контрольная группа). Все больные получали стандартную противовирусную терапию интерфероном-аи рибавирином в течение 24 недель. Вирусная нагрузка оценивалась на 4,12 и 24 неделях лечения. Полученные предварительные данные свидетельствуют об отсутствии негативного влияния хронического описторхоза на характер вирусологического ответа у больных хроническим гепатитом С в течение 24 недель противовирусной терапии

OPTIMIZATION OF PRESENTATION AND CONSUMER CONTAINER OF ANTI-RABIES IMMUNOGLOBULIN OBTAINED FROM HORSE SERUM

We presented the data concerning optimization of presentation and consumer container of anti-rabies immunoglobulin obtained, from horse serum.. During the experiments, ampoules and. flasks were used for primary packaging. They were filled within 5 ml of the preparation of freeze-drying. Comparative analysis of physical, chemical and. biological properties and. molecular parameters of freeze-dried and initial forms of the immunoglobulin. was carried out. Freeze-drying was demonstrated to promote stabilization of its properties and. prevent emergence of fragments and. aggregates during anti-rabies immunoglobulin storage

Plasma cytokines in patients with COVID-19 during acute phase of the disease and following complete recovery

COVID-19, an infection caused by the new coronavirus SARS-CoV-2, is associated with a number of pathophysiological mechanisms, mobilizing a wide spectrum of biomolecules, mainly, cytokines.The purpose of this study was to evaluate levels of multiple cytokines in blood plasma from the patients with COVID-19 during acute phase of the disease, and upon complete recovery. Samples of peripheral blood plasma of 56 patients with COVID-19, 69 convalescents and 10 healthy individuals were examined. Concentrations of 46 molecules, such as IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-9, IL-12 (p40), IL-12 (p70), IL-13, IL-15, IL-17A/CTLA8, IL-17-E/IL-25, IL-17F, IL-18, IL-22, IL-27, IFNα2, IFNγ, TNFα, TNFβ/ Lymphotoxin-α (LTA), CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, CCL7/MCP-3, CCL11/Eotaxin, CCL22/MDC, CXCL1/GROα, CXCL8/IL-8, CXCL9/MIG, CXCL10/IP-10, CX3CL1/Fractalkine, IL-1ra, IL-10, EGF, FGF-2/FGF-basic, Flt3 Ligand, G-CSF, M-CSF, GM-CSF, PDGF-AA, PDGF-AB/ BB, TGF-α, VEGF-A were measured via xMAP multiplexing technology. Significantly increased levels of 18 cytokines were found in blood plasma from COVID-19 patients during acute phase of the disease (as compared to control group), i.e., IL-6, IL-7, IL-15, IL-27, TNFα, TNFβ/Lymphotoxin-α (LTA), CCL2/MCP-1, CCL7/MCP-3, CXCL1/GROα, CXCL8/IL-8, CXCL10/IP-10, CXCL9/MIG, IL-1rа, IL-10, M-CSF, GM-CSF, VEGF-A. We found a significant decrease of nearly all the mentioned cytokines in recovered patients, in comparison with those who had moderate, severe/extremely severe disease. Moreover, we revealed a significantly decreased level of 8 cytokines in plasma from convalescents, as compared with control group, i.e., IL-1α, IL-2, IL-9, IL-12 p40, IL-18, CCL22/MDC, Flt3 Ligand, TGF-α. Immune response caused by SARS-CoV-2 infection involves multiple cytokines, mostly, with pro-inflammatory effects. We have shown for the first time that the convalescence phase is characterized by significantly lower levels of cytokines which regulate cellular differentiation and hematopoiesis (in particular, lymphocytes, T-cells and NK-cells). Over acute phase of the disease, the levels of these cytokines did not change. We revealed a significant decrease of most plasma cytokines upon recovery as compared to acute phase. On the contrary, acute phase of the disease is accompanied by significant increase of both pro- and antiinflammatory cytokines in blood plasma