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10th International Conference on Laser and Fiber-Optical Networks Modeling (LFNM 2010). 2nd IEEE International Workshop on THz Radiation: Basic Research and Applications (TERA 2010)
Electrical dc conductivity and laser damage threshold of pure and urea doped KH2PO4 crystals are investigated. It is found that the crystals with a low electrical conductivity have a high laser damage threshold. It is shown that increase of the resistivity and the laser damage threshold of the crystals realizes by the crystal growth from urea-containing aqueous solutions. The optimum molar value of...
The process of photon emission, that accompany photon pair production in strong magnetic field has been studied in nonresonant case. Angle dependence and dependence on final photon polarization are analyzed for this process. Total probability for the nonresonant process of photon emission 106 s-1 is three order of magnitude less, than resonant one.
The one-dimensional dielectric photonic crystals with complex defect layers, consisting of ultrathin superconducting and dielectric sublayers are theoretically studied. The pronounced difference in the transmittivity spectra of the photonic crystals with right-handed and left-handed positions of the superconducting defect sublayer with respect to the dielectric defect sublayer is demonstrated. The...
We study de nonlinear optical properties of organic materials. Multiple rings appear as a CW Ar laser passes through a nonlinear organic liquid. The rings formation is due to spatial self-phase modulation and is observed with 50 mW of continuous wave of Ar laser. We show the dependence between power and rings formed. As a first approximation to value the nonlinear refractive index we use the number...
We analyze applicability of the ε" <; 0 approximation to wave propagation in active material, comparing the results to the FDTD-based calculation employing more general Maxwell-Bloch model. It is shown that the slab thickness should be less than some critical value, corresponding to the divergence of the Airy series and to the start of the laser generation.
The main requirements for the MCT (CdxHg1-xTe) structures optimization for increase of the stimulated emission wavelength under optical pumping are discussed. The stimulated emission at wavelengths 2-2.5 μm at room temperature from optimized MCT structures is observed experimentally. The obtained experimental data are the first observation of stimulated emission from the MCT structures at these wavelengths...
Two types of superluminescent diodes (SLDs) based on DQW (InGa)As/(GaAl)As/GaAs nanostructures with 25 μm-width multimode active channels emitting at 890 nm and 950nm were studied. They ensure CW optical power of more than 100 mW ex standard 50 μm multimode fiber (MMF).
A fiber with a sinusoidal modulation of core diameter was fabricated. Management of the soliton fission by means of this fiber is demonstrated experimentally. Effect of stimulated Raman scattering on the soliton fission is discussed. The experimental observations are confirmed through numerical simulations.
Using the sol-gel technique, BaTiO3 was embedded in opal matrices that are the lattice packings of silica dioxide nanospheres for the first time. The room-temperature IR and Raman spectra clearly show characteristic vibrational modes of the ferroelectrically distorted TiO6 octahedra without any long-range order. Raman spectra bring evidence of a diffuse ferroelectric phase transition in the opal-BaTiO...
The fine structure of the spectral distribution of the time-averaged radiation power of four electrons moving one by one along the spiral in transparent medium in relativistic case is studied. The regime of super-radiance in synchrotron-Cherenkov radiation spectrum of four electrons moving in spiral above the Cherenkov threshold is investigated.
Spontaneous emission of a quantum dot placed in a 1D photonic band gap structure is analytically studied. Part of energy which remains nonradiated is obtained. It is shown that decay first follows ~t-1/2 law changing to ~t-3/2 law. Analytical expression for the spectrum is obtained. Analytical theory of the Borrmann effect is developed.
In excimer lasers Chang's profile and Ernst's profile are widely used. At relation of value of interelectrode distance (h) to electrodes width (b) h/b> 0,5 significant heterogeneity of electric field on coordinate Y takes place. Research of electric field spatial dependence was carried out with help of conformal transformations application.
Polariton modes in quantum-well traps for Bose-condensation of excitons are studied. It is found that some modes can become unstable and start lasing due to exciton spectrum narrowing during condensation. A model of such lasing is developed, showing different lasing regimes and possible coherent features of recombination emission of excitons.
We demonstrate an explicit numerical method for accurate calculation of the scattering matrix, and its poles, and apply this method to describing the multi-channel holes scattering in multiple-quantum-wells (MQW) structures. The results of calculations show that in contrast to the single quantum-well case, at some values of MQW parameters the number of S-matrix poles may exceed that of the absolute...
The map of dynamic regimes of a dual-wavelength vertical external cavity surface-emitting laser is built. The areas of continuous wave operation as well as of time-periodic, quasi-periodic and chaotic operation can be marked out in the map. A possible explanation of quite different laser behavior in those area is given.
Microscopic statistical theory of inhomogeneous broadening in InGaN/GaN quantum-well structures is developed. It is shown that inhomogeneous broadening can be described as energy-dependent daphasing time. Explicit relation between inhomogeneous broadening and spectral power density of the lateral interface potential fluctuations is derived.
Theoretical model of how LBIC signal from p-n junction being scanned by two laser beams is formed was proposed. Physical effects which make impact in overall phase of the LBIC signal were pointed out. Experimental research of illuminating surface of laser diode was conducted. Experimental dependencies of the phase of LBIC signal on the coordinate of scanning laser beams were obtained. Possibilities...
Using numerical modeling, influence of tuning the lasing frequency within the gain band on the modulation response of quantum-well heterolasers in the GaInAs-GaInAsP system versus the modulation frequency of pump current is investigated. It is established that maximum values of the frequency width of the response band and possibilities of realization of high-speed regimes at signal transmission in...
In the given paper we proposed an effective finite-difference scheme for a two-dimensional problem of femtosecond pulse influence on a semiconductor in the case of nonlinear dependence of light energy absorption coefficient on electric field potential.
Modeling of the random lasing in diffusive regime by Monte-Carlo method and Kubelka-Munk theory has been carried out. It has been obtained the experiment-corresponded dependencies of radiation parameters on media characteristics. The optimal samples parameters for effective lasing have been found.
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