Experimental and numerical study of different mode-locking techniques in holmium fiber laser with a ring cavity.

Experimental and numerical study has been performed for three techniques of mode-locking in all-fiber Holmium laser. We have compared the fundamental repetition rate pulsed generation for mode-locking based on: nonlinear polarization evolution, polymer-free single-walled carbon nanotubes, and hybrid mode-locking. Experimental and numerical simulation results demonstrated the shortest pulse duration and maximum spectrum width for mode-locking based on the nonlinear polarization evolution: 1.

Subcutaneous efgartigimod PH20 in generalized myasthenia gravis: A phase 3 randomized noninferiority study (ADAPT-SC) and interim analyses of a long-term open-label extension study (ADAPT-SC+).

ADAPT-SC (NCT04735432) was designed to evaluate noninferiority of subcutaneous (SC) efgartigimod PH20 to intravenous (IV) efgartigimod in participants with generalized myasthenia gravis (gMG). ADAPT-SC+ (NCT04818671) is an open-label extension study designed to assess long-term safety, tolerability, and efficacy of efgartigimod PH20 SC. Adult participants in ADAPT-SC were randomly assigned to receive a treatment cycle of 4 once-weekly administrations of efgartigimod PH20 SC 1000 ​mg or efgartigimod IV 10 ​mg/kg, followed by 7 weeks of follow-up.

Flat-topped optical spectrum as a specific marker of multi-pulse grouping in a soliton fiber laser.

We report the experimental observation of a stable generation regime in a soliton fiber laser, characterized by a distinct flat-topped optical spectrum. Notably, in multi-pulse generation, this specific spectrum shape prevents the harmonic mode-locking state, instead connecting the solitons into bound complexes or tight chaotic bunches. Physically, this suggests that in the observed regime, long-range attractive forces dominate over the inter-pulse repulsion across the entire laser cavity.

Newest Methods and Approaches to Enhance the Performance of Optical Frequency-Domain Reflectometers.

In this review, we summarize the latest advances in the design of optical frequency-domain reflectometers (OFDRs), digital signal processing, and sensors based on special optical fibers. We discuss state-of-the-art approaches to improving metrological characteristics, such as spatial resolution, SNR, dynamic range, and the accuracy of determining back reflection coefficients. We also analyze the latest achievements in the OFDR-based sensors: the accuracy of spatial localization of the impact, the error in detecting temperatures, deformation, and other quantities, and the features of separate measurement of various physical quantities.

Concepts and principles for new rapid simple liquid chromatography method for quantification of antioxidants resveratrol, vitamin E, and coenzyme Q10 in capsules with high-performance liquid chromatography with a photo-diode array detector.

Principles and problems in the development of simultaneous liquid chromatography (LC) analytical methods for potent antioxidative molecules resveratrol, tocopherol, and coenzyme Q10 in capsules, have been investigated and systematically compared and summarized. For these purposes, experiments within the full polarity spectrum of LC techniques. were tested and recorded.

[POEMS-syndrome].

POEMSsyndrome (polyneuropathy - P, organomegaly - O, endocrinopathy - E, M-protein - M, skin changes - S) is a paraneoplastic syndrome caused by underlying dyscrasia of plasma cells. The main criteria of the syndrome are polyradiculoneuropathy, clonal proliferation of plasma cells, sclerotic bone lesions, elevated levels of vascular endothelial growth factor and the presence of Castleman disease. Additional signs include organomegaly, endocrinopathy, characteristic skin changes, edema of the optic disc, extravascular volume overload (edema) and thrombocytosis.

Supermode noise mitigation and repetition rate control in a harmonic mode-locked fiber laser implemented through the pulse train interaction with co-lased CW radiation: publisher's note.

This publisher's note contains corrections to Opt. Lett.47, 5236 (2022)10.

Corrigendum to "CLIPPERS: Multiparametric and quantitative MRI features" [Radiology Case Reports 18 (2023) 368-376].

[This corrects the article DOI: 10.1016/j.radcr.

Brillouin Interaction between Two Optical Modes Selectively Excited in Weakly Guiding Multimode Optical Fibers.

A multimode optical fiber supports excitation and propagation of a pure single optical mode, i.e., the field pattern that satisfies the boundary conditions and does not change along the fiber.

CLIPPERS: Multiparametric and quantitative MRI features.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare chronic central-nervous-system inflammatory disorder that became known only recently, and the pathogenesis of CLIPPERS remains poorly understood. This report presents clinical and radiological features of a rare case: a young female patient who rapidly died of suspected CLIPPERS. Helpful multiparametric MRI diagnostic criteria are proposed that can help discriminate CLIPPERS from non-CLIPPERS pathologies.

Resonantly induced mitigation of supermode noise in a harmonically mode-locked fiber laser: revealing the underlying mechanisms.

We have performed experimental and numerical studies enabling clear insight into the physical mechanisms underlying the super-mode noise mitigation in harmonically mode-locked (HML) fiber lasers using the resonant continuous wave (CW) injection. New experiments have refined the requirements to the positions inside the laser spectrum assigned to the injected CW component, a Kelly sideband, and the transparency peaks of the birefringent fiber filter. In particular, we have proved experimentally that the noise mitigation effect is dominating with the CW injected to the long-wavelength side of laser spectrum.

Supermode noise mitigation and repetition rate control in harmonic mode-locked fiber laser implemented through the pulse train interaction with co-lased CW radiation.

We report on new, to the best of our knowledge, techniques enabling both the mitigation of supermode laser noise and highly precise setting of the pulse repetition rate (PRR) in a soliton harmonically mode-locked (HML) fiber laser employing nonlinear polarization evolution (NPE). The principle of operation relies on resonant interaction between the soliton pulses and a narrowband continuous wave (CW) component cooperatively generated within the same laser cavity. In contrast to our recent findings [Opt.

[Approaches to vaccine prevention in multiple sclerosis].

The article presents an overview of modern approaches to vaccine prevention in multiple sclerosis (MS). Compared with the general population, patients with MS have been shown to have an increased risk of morbidity, a tendency to have a more severe course, and a greater mortality from vaccine-preventable infections. At the same time, in Russia, until recently, traditionally adhered to a conservative tactic of limiting vaccination in patients with autoimmune diseases, including MS.

[Long-term treatment for multiple sclerosis with interferon beta-1b. Outcomes of an open, retrospective, observational study].

Objective: To assess the outcomes of long-term treatment in multiple sclerosis (MS) patients with Infibeta (interferon beta-1b).

Material And Methods: The article presents the results a real-world, multicenter, retrospective, observational study of treatment with interferon beta-1b. We enrolled 332 patients with MS who had been receiving Infibeta for at least 8 years.

[Local experience of IL-6 pathway inhibition with satralizumab for patients with neuromyelitis optica spectrum disorder].

Satralizumab is a monoclonal anti-IL6-anibody for patients with neuromyelitis optica or neuromyelitis optica spectrum disorder (NMOSD) seropositive for anti-AQP4-antibody. Satralizumab has been approved in 2021 in the Russian Federation for usage in adults and adolescents from 12 years and older in combination with basic therapy or in monotherapy. The efficacy and safety of satralizumab in comparison with placebo have been demonstrated in two international randomized clinical trials SakuraStar and SakuraSky, phase III.

Scientific Applications of Distributed Acoustic Sensing: State-of-the-Art Review and Perspective.

This work presents a detailed review of the development of distributed acoustic sensors (DAS) and their newest scientific applications. It covers most areas of human activities, such as the engineering, material, and humanitarian sciences, geophysics, culture, biology, and applied mechanics. It also provides the theoretical basis for most well-known DAS techniques and unveils the features that characterize each particular group of applications.

Brillouin-like amplification in rare-earth-doped optical fibers.

We present a theoretical formalism to describe the amplification of two monochromatic waves counter-propagating in a rare-earth-doped optical fiber amplifier. Interaction of the waves through a dynamical population inversion grating inscribed in the active fiber by the waves during their amplification results in a strong power transfer from one wave to another providing a preferable amplification of one wave at the expense of another. In this sense, the effect is similar to stimulated Brillouin scattering and is expected to be observed with both pumped and unpumped rare-earth-doped fibers possessing a finite polarizability difference between the excited and ground states.

Amplifier similariton fiber laser with a hybrid-mode-locking technique.

By employing both frequency shifting and nonlinear polarization rotation mechanisms in a Yb-doped fiber laser, similariton operation regime is demonstrated. Directly generated pulses from an oscillator has a duration of 7.8 ps with 20.

Mitigation of the supermode noise in a harmonically mode-locked ring fiber laser using optical injection.

We report on a new, to the best of our knowledge, technique enabling mitigation of the supermode noise (and timing jitter) in a soliton harmonically mode-locked (HML) fiber laser built on the nonlinear polarization evolution (NPE). An optical injection of an external continuous wave (CW) into the HML laser cavity results in an increase of the supermode noise suppression level (SSL) by a two-three order of magnitude for harmonics between 25th and 135th. The operation mechanism involves phase-locking between the injected light and soliton pulses and exhibits strong resonant dependence on the CW laser wavelength.

Pulse repetition rate tuning of a harmonically mode-locked ring fiber laser using resonant optical injection.

We report on a new, to the best of our knowledge, technique enabling fine-tuning of the pulse repetition rate (PRR) of a soliton harmonically mode-locked (HML) fiber laser built on the nonlinear polarization evolution (NPE). Optical injection of an external continuous wave (CW) into the HML laser cavity is used for this purpose enabling precise PRR tuning with the elementary step equal to the fundamental PRR one-by-one. The effect exhibits strong resonance dependence on the CW laser wavelength and available in both positive and negative directions.

Application of Dual-Frequency Self-Injection Locked DFB Laser for Brillouin Optical Time Domain Analysis.

Self-injection locking to an external fiber cavity is an efficient technique enabling drastic linewidth narrowing of semiconductor lasers. Recently, we constructed a simple dual-frequency laser source that employs self-injection locking of a DFB laser in the external ring fiber cavity and Brillouin lasing in the same cavity. The laser performance characteristics are on the level of the laser modules commonly used with BOTDA.

[Clinical and epidemiological aspects of neuromyelitis optic spectrum diseases in the russian population].

Objective: To present clinical and epidemiological aspects of neuromyelitis optica spectrum disorders (NMOSD) in the Russian Federation.

Material And Methods: We studied 142 patients who met diagnostic criteria of 2015 for NMOSD. Sex, age at disease onset, presence or absence of aquaporin-4 immunoglobulin G antibodies (AQP4-IgG), mail clinical symptoms, oligoclonal IgG, therapy for the treatment of exacerbations and prevention of exacerbations, compliance with 2006 diagnostic criteria were assessed.

Dual-frequency laser comprising a single fiber ring cavity for self-injection locking of DFB laser diode and Brillouin lasing.

Low-noise lasers are a powerful tool in precision spectroscopy, displacement measurements, and development of advanced optical atomic clocks. While all applications benefit from lower frequency noise and robust design, some of them also require lasing at two frequencies. Here, we introduce a simple dual-frequency laser leveraging a ring fiber cavity exploited both for self-injection locking of a standard semiconductor distributed feedback (DFB) laser and for generation of Stokes light via stimulated Brillouin scattering.

All-fiber polarization-maintaining mode-locked laser operated at 980 nm.

For the first time, to the best of our knowledge, we present an all-fiber polarization-maintaining passively mode-locked picosecond laser operated at 980 nm. The laser cavity had a ring configuration with a semiconductor saturable absorber mirror as a mode-locking element. As an active medium, we used a specially designed cladding-pumped Yb-doped fiber with reduced cladding-to-core diameter ratio.

Detuning effects in Brillouin ring microresonator laser.

Brillouin lasers, with their unique properties, offer an intriguing solution for many applications, yet bringing their performance to integrated platforms has remained questionable. We present a theoretical framework to describe Brillouin lasing in integrated ring microcavities. Specifically, a general case of a mismatch between the Brillouin shift and the microresonator inter-mode spacing is considered.