Passively Q-switched Er-Yb double clad fiber laser with Cr²⁺:ZnSe and Co²⁺:MgAl₂O₄ as a saturable absorber

Passive Q-switching of fiber lasers with saturable absorbers have attracted attention because of simplicity and high efficiency. However, the number of known materials which can be used as a saturable absorber is relatively limited due to the features of fiber lasers. While liquefying gallium mirror, semiconductor structures (SESAM), as well as Co as saturable absorbers

Feasibility studies for the measurement of time-like proton electromagnetic form factors from p¯ p→ μ+μ- at P ¯ ANDA at FAIR

This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, | GE| and | GM| , using the p¯ p→ μ+μ- reaction at P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is p¯ p→ π+π-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented

Study of doubly strange systems using stored antiprotons

Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P‾ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ−-atoms will be feasible and even the production of Ω−-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ω−-nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions

Doped YVO₄ crystals: growing, properties and applications

Results of growing YVO₄ crystals doped with Nd, Er, Yb, Сr are given. Problems of obtaining crystals of high optical quality are discussed. Spectral and generating characteristics of these crystals are discussed. Spectral data of Сr⁵⁺ in YVO₄ are given. They suggest to create active laser medium with passive Q-switching in single Nd³⁺, Сr⁵⁺:YVO₄ crystal.Приведено результати вирощування кристалiв YVO₄, активованих Nd, Er, Yb, Cr. Обговорюються питання отримання кристалiв високої оптичної якостi. Представлено їх спектроскопiчнi i генерацiйнi характеристики. Приведено спектральнi данi Сr⁵⁺ в YVO₄ якi припускають створення в одному кристалi Nd³⁺, Сr⁵⁺:YVO₄ середовища з пасивною модуляцiєю добротностi.Приведены результаты выращивания кристаллов YVO₄, активированных Nd, Er, Уb, Cr. Обсуждаются вопросы получения кристаллов высокого оптического качества. Представлены их спектроскопические и генерационные характеристики. Приведены спектральные данные Сr⁵⁺ в YVO₄ которые предполагают создание в одном кристалле Nd³⁺, Сr⁵⁺ :YVO₄ . Активной лазерной среды с пассивной модуляцией добротности

Absorption saturation properties and laser Q-switch performance of Cr5+-doped YVO4 crystal

The ground-state and excited-state absorption cross sections of a Cr5+:YVO4 single crystal were determined by the intensity-dependant transmission measurements to be(2.0±0.4)×10-18 cm2 and less than 0.1×10-18 cm2 at 1.08 μm, respectively. The bleaching relaxation time of the Cr5+:YVO4 crystal was estimated to be 3.5±1.5 ns. Passive Q-switching of a diode-pumped Yb3+:YVO4 laser with the Cr5+:YVO4 saturable absorber was realized

Femtosecond pulse operation of a Tm,Ho-codoped crystalline laser near 2 μm

We demonstrate, for the first time to our knowledge, femtosecond-regime mode locking of a Tm,Ho-codoped crystalline laser operating in the 2 m spectral region. Transform-limited 570 fs pulses were generated at 2055 nm by a Tm,Ho:KYWO42 laser that produced an average output power of 130 mW at a pulse repetition frequency of 118 MHz. Mode locking was achieved using an ion-implanted InGaAsSb quantum-wellbased semiconductor saturable absorber mirror

Growth, spectroscopy and continuous-wave laser performance of Nd³⁺:LiLu_0.65Y_0.35F₄ crystal

A mixed fluoride crystal of LiLu0.65Y0.35F4 doped with Nd3+ ions was grown by the Bridgman–Stockbarger method. Polarized absorption and luminescence spectra as well as luminescence lifetime were measured at room temperature. Emission probabilities, branching ratios and radiative lifetime were studied within the Judd–Ofelt theory and the emission cross section spectra were calculated. Efficient continuous wave laser operation was demonstrated with the crystal. A maximum output power of 7.7 W and slope efficiency of 60% were achieved at 1047 nm for the TEM00 mode