Tunable third-harmonic generation in a solid-core tellurite glass fiber

A solid-core tellurite glass fiber with 1.8?dB/m loss at 1.55?μm was made by using the built-in casting preform fabrication method and rod-in-tube fiber drawing technique. Pumping a 10?cm fiber piece with picosecond pulses of 3-5×10(12)?W/cm(2), 0.1% of the fundamental power limited by the coherence length of 0.3-5?μm was converted into visible third-harmonic power tunable over a broad near-IR wavelength ranging from 1500 to 1680?nm. Frequency conversion from the mid-IR to near-IR was found to be even more efficient due to the longer coherence lengths of 12-20?μm in the wavelength range of 2200-2500?nm.     

Slow light on a printed circuit board

Slow-light effects induced by stimulated Raman scattering in polymer waveguides on a printed circuit board are shown to enable a widely tunable delay of broadband optical signals, suggesting an advantageous platform for optical information processing and ultrafast optical waveform transformation.     

Ionization penalty in nonlinear Raman neuroimaging

Light-assisted ionization accompanying coherent anti-Stokes Raman scattering (CARS) of ultrashort laser pulses in brain tissue is shown to manifest itself in a detectable blueshift of the anti-Stokes signal. This blueshift can serve as an indicator of ionization processes in CARS-based neuroimaging.     

Numerical Simulation of the Tube Flow of a Mixture with Chemical Reactions and Condensation

The results of calculating a model of a direct-flow chemical vapor-deposition reactor are presented. The phase- formation stages are considered over a wide time range. This makes it possible to identify different flow structures in which interference between the heat and mass transfer and chemical condensation processes occurs.     

Mechanism of PbSe y S1 − y film formation in chemical deposition from aqueous solutions

The growth mechanism of PbSe _y S_{1 ? y} films has been studied upon chemical deposition from aqueous solutions using scanning probe microscopy. A comparative morphological analysis of layers deposited at the initial growth stages and the use of fractal formalism shows that the formation of films of PbS, PbSe, and PbSe _y S_{1 ? y} substitutional solid solutions involves cluster-cluster aggregation with self-organization elements.     

Steady-state solutions of the Vlasov-Maxwell system and their stability

The study of the Vlasov-Maxwell system is reduced to nonlinear elliptic equations in the stationary case and hyperbolic equations in the nonstationary case. On this basis, theorems on the existence of solutions and sufficient conditions of Lyapunov stability are obtained. The cases are considered when electromagnetic fields and distribution functions can be constructed in an implicit form.     

Diffuse X-ray scattering and nanoclusters in the Hg2Br2 model ferroelastics

Diffuse maxima are revealed and studied for the first time in the x-ray scattering patterns of Hg₂Br₂ single crystals. These maxima originate from clusters of the orthorhombic phase due to the phase transition in the paraphase tetragonal matrix. The nucleation and growth of clusters are initiated by spatiotemporal fluctuations of the order parameter corresponding to the soft transverse acoustic mode at X points of the Brillouin zone boundary. Information on the behavior of the susceptibility and correlation length with variations in temperature and on the shape and anisotropy of the clusters is obtained, and the critical exponents are determined.