Spatial beam self-cleaning and supercontinuum generation with Yb-doped multimode graded-index fiber taper based on accelerating self-imaging and dissipative landscape

We experimentally demonstrate spatial beam self-cleaning and supercontinuum generation in a tapered Ytterbium-doped multimode optical fiber with parabolic core refractive index profile when 1064 nm pulsed beams propagate from wider (122 µm) into smaller (37 µm) diameter. In the passive mode, increasing the input beam peak power above 20 kW leads to a bell-shaped output beam profile. In the active configuration, gain from the pump laser diode permits to combine beam self-cleaning with supercontinuum generation between 520-2600 nm. By taper cut-back, we observed that the dissipative landscape, i.e., a non-monotonic variation of the average beam power along the MMF, leads to modal transitions of self-cleaned beams along the taper length

Identity and integration of Russian speakers in the Baltic states: a framework for analysis

Following a review of current scholarship on identity and integration patterns of Russian speakers in the Baltic states, this article proposes an analytical framework to help understand current trends. Rogers Brubaker's widely employed triadic nexus is expanded to demonstrate why a form of Russian-speaking identity has been emerging, but has failed to become fully consolidated, and why significant integration has occurred structurally but not identificationally. By enumerating the subfields of political, economic, and cultural ‘stances’ and ‘representations’ the model helps to understand the complicated integration processes of minority groups that possess complex relationships with ‘external homelands’, ‘nationalizing states’ and ‘international organizations’. Ultimately, it is argued that socio-economic factors largely reduce the capacity for a consolidated identity; political factors have a moderate tendency to reduce this capacity, whereas cultural factors generally increase the potential for a consolidated group identity

NEW APPROACHES TO THE ORGANIZATION OF SKIN CANCER SCREENING

Skin cancer is the most common type of cancer in the Russian Federation. Despite the high incidence rate of skin cancer, there is no single standard for screening to identify this disease at an early stage, therefore, screening programs for detecting premalignant lesions and skin cancer at early stages are of great importance. The article describes the results of the action dedicated to the World Day against melanoma, held in Krasnoyarsk Regional Clinical Oncology Center named after A.I. Kryzhanovsky. Selection of participants was based on electronic applications, including photographs of skin lesions taken by the patients themselves. Out of the 343 people who applied, 143 (41.7 %) persons were selected for physician’s consultation. There were revealed 6 cases of melanoma, 13 basal cell tumors, and 1 lymphoproliferative disorders of the skin

Nonlinear beam cleanup in Yb-doped GRIN multimode fiber taper

We demonstrate beam self-cleaning in a tapered Ytterbium-doped graded- index multimode fiber in both active and passive configurations, without accompanying self-phase modulation induced spectral broadening or frequency conversio

НОВЫЕ ПОДХОДЫ К ОРГАНИЗАЦИИ СКРИНИНГА ЗЛОКАЧЕСТВЕННЫХ НОВООБРАЗОВАНИЙ КОЖИ

Skin cancer is the most common type of cancer in the Russian Federation. Despite the high incidence rate of skin cancer, there is no single standard for screening to identify this disease at an early stage, therefore, screening programs for detecting premalignant lesions and skin cancer at early stages are of great importance. The article describes the results of the action dedicated to the World Day against melanoma, held in Krasnoyarsk Regional Clinical Oncology Center named after A.I. Kryzhanovsky. Selection of participants was based on electronic applications, including photographs of skin lesions taken by the patients themselves. Out of the 343 people who applied, 143 (41.7 %) persons were selected for physician’s consultation. There were revealed 6 cases of melanoma, 13 basal cell tumors, and 1 lymphoproliferative disorders of the skin.Злокачественные новообразования кожи занимают первое место в структуре онкологической заболеваемости в Российской Федерации и по темпам прироста имеют лидирующие позиции наряду со злокачественными опухолями легких и молочных желез. Несмотря на большую распространенность данной патологии, не существует единого стандарта скрининга для выявления болезни на ранней стадии. Это определяет актуальность создания программ для выявления предраковых заболеваний и злокачественных новообразований кожи на ранних стадиях. В статье описываются результаты акции, приуроченной к Всемирному дню борьбы с меланомой кожи, проведенной в КГБУЗ «Красноярский краевой клинический онкологический диспансер им. А.И. Крыжановского». В течение месяца проводился предварительный отбор участников акции на основании электронных заявок, включавших фотографии новообразований кожи, выполненных самими пациентами. Из 343 человек, подавших заявку, 143 (41,7 %) человека были отобраны для очной консультации. В итоге акции выявлено 6 случаев меланомы, 13 базально-клеточных опухолей, а также одно лимфопролиферативное заболевание кожи

INVESTIGATION OF INFLUENCE OF REGIMES OF THERMAL PROCESSING ON STRUCTURE AND MECHANICAL CHARACTERISTICS OF HOT-ROLLED TUBES, PRODUCED OF STEEL 32G2

Investigations on influence of heating temperature, cooling regimes and steady temperature on structure and mechanical characteristics of hot-rolled pipes, produced of steel 32G2, are carried out

Mode-locked all-solid photonic bandgap fiber laser

International audienceWe report on a mode-locked all-normal dispersion fiber laser featuring a large-mode-area all-solid photonic bandgap fiber. The self-starting chirped-pulse laser delivers 660 mW of average power at a repetition rate of 30 MHz, leading to 22 nJ energy. The output pulses are dechirped outside the cavity to nearly transform-limited duration of 50 fs. Numerical simulations are in good agreement with experiments and highlight the key role of passive spectral filtering on pulse shaping

Ytterbium Lasers Based on P 2 O 5 -and Al 2 O 3 -doped Fibers

Abstract Starting from measured cross-sections of Yb ions in Introduction The power of Yb-doped cladding-pumped fiber lasers progressively increases and have already exceeded 1 k