Search

One of the prime applications of squeezed light is enhancing the sensitivity of an interferometer below the quantum shot-noise limit, but so far, no such experimental demonstration was reported when using the optical Kerr effect. In prior setups involving Kerr-squeezed light, the role of the interferometer was merely to characterize the noise pattern. The lack of such a demonstration was largely due to the cumbersome tilting of the squeezed ellipse in phase space. Here, we present the first experimental observation of phase-sensitivity enhancement in an interferometer using Kerr squeezing.

Mid-IR fiber lasers operating at wavelengths near 5 μm are of great interest for many fundamental and industrial applications, but only a few experimental samples based on active chalcogenide fibers have been demonstrated so far. One of the limitations of the power of such lasers may be a fairly low fiber damage threshold. To solve this problem, we developed and numerically investigated in detail a mid-IR fiber laser at 5.3 µm with multi-W output power pumped into the cladding at a wavelength of 2 µm. We proposed using a Tb-doped chalcogenide multicore fiber with 25 single-mode cores arranged in a 5 × 5 square lattice as an active medium. The proposed laser design surpasses the power limit of single-core chalcogenide fibers. When simulating lasers, we specified realistic parameters of Tb-doped chalcogenide glass based on published experimental data. We performed a comprehensive theoretical analysis, studied the influence of various factors on the characteristics of generation, and found optimal system parameters and expected generation parameters. [ABSTRACT FROM AUTHOR]

The article is devoted to the cognitive emotiological concept of pride. The relevance of the study lies in the fact that the compilation of conceptual lexical “portraits” and their subsequent comparison in different languages will reveal the similarity and difference in the natural language metaphysics of the compared cultures. Developed new author’s technique of “lexical portraying” of the concept determines the novelty of the research. The linguistic material of the research was the data from the corpus dictionaries “British National Corpus (BNC)” and “Russian National Corpus (RNC)” which represent a collection of grammatically marked texts. The first part of the article highlights the relevance of the study, defines the term “emotiological concept”, as well as provides general and specific for this area of research discussion issues from the field of cultural and cognitive linguistics. The authors analyze the interpretation of the term “concept”, the scope and content of this meaning and the ways of its description. The second part of the article is devoted to the study of the cognitions of “a proud man” and “a prideful man”. The authors conclude that the actualization of emotional feelings occurs under the influence of both external (socially conditioned) and internal (psychological) factors – the “provocateurs”. The third part presents the results of the cognitive analysis of the concepts “pride” and “гордость”. To provide this the authors refer to the definition of the realeme (a unit of the given lexical system). The ontogeny of the characterological behavioral qualities of “a proud man” and “a prideful man” is traced, and the amount of semantic and pragmatic information is established. Based on the analysis of the empirical vocabulary data and the considered connotations of lexical units “pride” and “гордость”, the authors propose a new type of “lexical portraying” and provide in the article the sample of one for the concepts “pride” and “гордость”. The developed etymological entry of the concept indicates 1) the cognitive elements of the concept, 2) the socio-cultural elements of the concept, 3) the semantics of the concept and 4) the syntax of the concept. The article dwells on emphasizing the fact that it is the cognitive elements that are universal for both Russian and English, while sociocultural, semantic, and syntactic elements might not always coincide in different natural language metaphysics. In conclusion, the authors summarize the data of the study and outline the promising areas of work in the field of concept science and cognitive linguistics.

The development and investigation of miniature narrow-line coherent light sources based on microresonators with low-power-consumption whispering gallery modes (WGMs) is an actual trend in modern photonics. Raman WGM microlasers can operate at wavelengths inaccessible to traditional laser media and provide a huge pump frequency tuning range. Here, we propose and theoretically study multicascade Raman microlasers based on soft tellurite TeO2–WO3–Bi2O3 glass WGM microresonators (microspheres) which can operate in the near-IR and mid-IR with the pump in the telecommunication range. Thanks to a large Raman gain (120 times exceeding the maximum Raman gain of silica glass) and a huge Raman frequency shift of 27.5 THz for this glass, the Raman waves at 1.83 µm, 2.21 µm, 2.77 µm, and 3.7 µm in the first, second, third, and fourth cascades, respectively, are theoretically demonstrated with a pump at 1.57 µm. We analyze in detail the influence of different factors on the characteristics of the generated Raman waves, such as microsphere diameters, Q-factors, pump powers, and detuning of the pump frequency from exact resonance. We also solve a thermo-optical problem to show that the temperature of a soft glass microresonator heated due to partial thermalization of pump power remains below the glass transition temperature. To the best of our knowledge, mid-IR tellurite glass Raman WGM microlasers have not been studied before. [ABSTRACT FROM AUTHOR]

The development of high-power laser sources at 2.3 µm is highly demanded for remote sensing and other applications. However, this wavelength is poorly covered by present-day lasers. To obtain 100 W class high-power radiation at 2.3 μm, we propose to use simultaneously cascade laser amplification at 2 and 2.3 µm with a commercially available diode pump at 793 nm and stimulated Raman scattering between the amplified signal waves in a special zinc–tellurite multicore fiber with ten trivalent-thulium-ion-doped cores arranged in a ring. We demonstrate numerically that the use of an out-of-phase supermode (with spatial phases differing by π in neighboring cores) can provide up to 50% efficiency conversion from the 793 nm pump to the 2.3 µm wave. [ABSTRACT FROM AUTHOR]

Fiber laser sources operating near 2300 nm in the atmospheric transparency window are interesting for different applications, such as remote sensing, lidars, and others. The use of Tm-doped fiber lasers based on tellurite fibers is highly promising. We propose and theoretically study a highly efficient diode-pumped Tm-doped zinc-tellurite fiber laser operating at two cascade radiative transitions at 1960 nm and 2300 nm, with additional energy transfer between these laser waves due to the Raman interaction. We demonstrate numerically that a dramatic increase in the slope efficiency up to 57% for the laser wave at 2300 nm, exceeding the Stokes limit by 22% relative to the pump at 793 nm, can be obtained with optimized parameters thanks to Raman energy transfer from the laser wave at 1960 nm to the wave at 2300 nm. [ABSTRACT FROM AUTHOR]

Glass microresonators with whispering gallery modes (WGMs) have a lot of diversified applications, including applications for sensing based on thermo-optical effects. Chalcogenide glass microresonators have a noticeably higher temperature sensitivity compared to silica ones, but only a few works have been devoted to the study of their thermo-optical properties. We present experimental and theoretical studies of thermo-optical effects in microspheres made of an As2S3 chalcogenide glass fiber. We investigated the steady-state and transient temperature distributions caused by heating due to the partial thermalization of the pump power and found the corresponding wavelength shifts of the WGMs. The experimental measurements of the thermal response time, thermo-optical shifts of the WGMs, and heat power sensitivity in microspheres with diameters of 80–380 µm are in a good agreement with the theoretically predicted dependences. The calculated temperature sensitivity of 42 pm/K does not depend on diameter for microspheres made of commercially available chalcogenide fiber, which may play an important role in the development of temperature sensors. [ABSTRACT FROM AUTHOR]