For the first time to our knowledge, multiwavelength, highly transient, single-pass stimulated Raman scattering with a low wavelength spacing on dual (stretching and bending) Raman modes in Sr(MoO)(WO) and Sr(MoO)(WO) solid solutions in a range of 1000-1300 nm (transparence window of biological tissue) under ultrafast chirped pulse laser pumping is comparatively investigated in the interests of multicolor two-photon imaging of a living tissue. For both the solid solutions, the optimum range (1-5 ps) of chirped pump pulse durations for multiwavelength Raman conversion on dual Raman modes was wider than for SrMoO (2-3 ps) due to the higher integral cross section of the bending Raman mode. Higher efficient SRS conversion took place at negative chirping of the pump pulse with its stretching from 0.
View Article and Find Full Text PDFLarge GaSe crystals were grown and various antireflection microstructures (ARMs) were fabricated on their cleaved surfaces using optimized femtosecond laser ablation, which provided the antireflection effect in a wide wavelength range of 4-16 µm. The influence of ARMs created on the GaSe surface on the change of the laser-induced damage threshold (LIDT) of the crystal at a wavelength of 5 μm was evaluated. The 5-µm Fe:ZnMgSe laser with the pulse duration of 135 ns was used for the LIDT test in conditions close to single pulse exposure.
View Article and Find Full Text PDFAim: To evaluate the changes in blood pressure (BP), the severity of pain syndrome and non-steroidal anti-inflammatory drugs (NSAIDs) use patterns in patients hospitalized for elective arthroplasty of large joints of the lower extremities during the postoperative period.
Materials And Methods: This study included 374 patients. In all patients, medical history, antihypertensive therapy and history of NSAIDs usage were collected, BP was measured, and the severity of pain was assessed via a 10-point scale before surgery, as well as 1 and 3 months after arthroplasty.
For the first time, to the best of our knowledge, we demonstrate highly transient, multiwavelength, single-pass Raman generation with combined frequency shifts on two Raman modes of an SrMoO crystal with high total Raman conversion efficiency of up to 48% in conditions of competition with self-phase modulation (SPM). A 58-mm-long SrMoO crystal was used as the active medium under pumping by the 1030-nm, 40-µJ laser pulses with controllable dispersive stretching in a range of 0.25-6 ps at negative and positive chirping.
View Article and Find Full Text PDFPeerJ Comput Sci
December 2022
As one of the major platforms of communication, social networks have become a valuable source of opinions and emotions. Considering that sharing of emotions offline and online is quite similar, historical posts from social networks seem to be a valuable source of data for measuring observable subjective well-being (OSWB). In this study, we calculated OSWB indices for the Russian-speaking segment of Twitter using the Affective Social Data Model for Socio-Technical Interactions.
View Article and Find Full Text PDFPeerJ Comput Sci
November 2022
Prior research suggests that weather conditions may substantively impact people's emotional state and mood. In Russia, the relationship between weather and mood has been studied for certain regions-usually with severe or extreme climatic and weather conditions-but with quite limited samples of up to 1,000 people. Over the past decade, partly due to the proliferation of online social networks and the development of natural language processing techniques, the relationship between weather and mood has become possible to study based on the sentiment expressed by individuals.
View Article and Find Full Text PDFPeerJ Comput Sci
July 2022
The Russian language is still not as well-resourced as English, especially in the field of sentiment analysis of Twitter content. Though several sentiment analysis datasets of tweets in Russia exist, they all are either automatically annotated or manually annotated by one annotator. Thus, there is no inter-annotator agreement, or annotation may be focused on a specific domain.
View Article and Find Full Text PDFIn this Letter, a mixed ()() as a new, to the best of our knowledge, active medium with optimized content for a synchronously pumped multiwavelength Raman laser with a combined frequency shift is presented. The unique structure of this crystal resulted in oscillations at 12 closely spaced output wavelengths in a spectral range from 1128 to 1360 nm. The strongest pulse shortening in comparison with nominally pure scheelite-like crystals has been achieved.
View Article and Find Full Text PDFFor the first time to our knowledge, the operation of a synchronously pumped ultrafast Raman laser that uses a PbMoO crystal as the active medium has been demonstrated. We achieved efficient Raman conversion in PbMoO from pumping 1063 nm into 1171 and 1217 nm, respectively, at single and combined frequency shifts on stretching and bending Raman modes. The output pulse energy (up to 160 nJ) and peak power (up to 11 kW) of the output picosecond radiation is the highest among all-solid-state synchronously pumped Raman lasers published to date.
View Article and Find Full Text PDFCollinear phase matching of the Stokes ↔ anti-Stokes interaction for Raman-active crystals with different birefringence was studied theoretically as well as experimentally. It was shown that collinear phase matching of the Stokes ↔ anti-Stokes interaction in low-birefringent crystals can be insensitive to angular mismatch if a phase matching angle is higher than 60. We have developed and experimentally realized an extracavity parametric Raman anti-Stokes laser based on a low-birefringent SrWO.
View Article and Find Full Text PDFThe present increase of attention toward blockchain-based systems is currently reaching a tipping point with the corporate focus shifting from exploring the technology potential to creating Distributed Ledger Technology (DLT)-based systems. In light of a significant number of already existing blockchain applications driven by the Internet of Things (IoT) evolution, the developers are still facing a lack of tools and instruments for appropriate and efficient performance evaluation and behavior observation of different blockchain architectures. This paper aims at providing a systematic review of current blockchain evaluation approaches and at identifying the corresponding utilization challenges and limitations.
View Article and Find Full Text PDFThe extracavity parametric Raman CaCO anti-Stokes laser at 954 nm excited by two orthogonally polarized (pump and probe) equal frequency laser beams was proposed and investigated. Tangential phase matching conditions for the orthogonally polarized Raman components four-wave mixing in the CaCO crystal at stimulated Raman scattering (SRS) under 1064-nm excitation were theoretically studied and applied for a novel nanosecond parametric Raman laser allowing to increase the 954-nm anti-Stokes generation efficiency. In agreement with the theoretical modeling, using the high-Q external cavity scheme we have experimentally achieved the highest optical-to-optical (1064 nm to 954 nm) efficiency of 4% in comparison with the known crystalline parametric Raman anti-Stokes lasers.
View Article and Find Full Text PDFWe present a highly efficient ring-cavity all-solid-state BaWO Raman laser generating at both the long-shift (ν=925 cm) and short-shift (ν=332 cm) Raman lines under external picosecond synchronous pumping at the wavelength of 1063 nm. Very high slope efficiencies and output pulse energies of 68.8% and 103 nJ at the ν-shifted Stokes wavelength of 1179 nm, and 38.
View Article and Find Full Text PDFOrtop Travmatol Protez
November 1970