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We report a study of a microwave discharge plasma excited in revolver silica fibers with a hollow core ∼100 μm in diameter. Temporal and spectral characteristics of the plasma glow are obtained for various inert gases and their mixtures filling the hollow core at different pressures. The hollow-core fiber demonstrates stability against the microwave discharge plasma that is maintained in the hollow core under periodically pulsed pumping with low enough duty cycle. [ABSTRACT FROM AUTHOR]

A new method for measuring the refractive index of crystals and melts at high temperatures is presented. The refractive index of an Er3+:YAG crystal melt is determined during the laser-heated pedestal growth process close to the melting point. The main idea is to use the maximal difference in the intensities of two polarizations of thermal radiation passing the melt-air interface. From the Fresnel equations, it follows that this difference is almost proportional to the refractive index. Angular diagrams of the thermal radiation of the melt for two polarizations are analyzed. The obtained value of the refractive index of the Er3+:YAG melt is n = 1.84 ± 0.01 in the wavelength range of 550–620 nm. [ABSTRACT FROM AUTHOR]

Phase distortions introduced into the laser beam propagating in a plate under diode pumping of the active element (AE) and for intentionally caused temperature gradients in the AE are studied. The temperature distribution along the optical axis of the active element is measured during its end diode pumping. Phase distortions of the test beam propagating through the nonuniformly heated active element are studied. Interference patterns are obtained and optical distortions of the test beam are measured at various temperature gradients in the crystal. [ABSTRACT FROM AUTHOR]

An efficient technology was developed for growing the gadolinium gallium garnet (GGG) single-crystal films doped with Nd3+ or Cr and Ca ions. The films with thickness up to 100 µm have been grown by liquid-phase epitaxy method on undoped GGG substrates of small and big sizes (5–8 mm and up to 76 mm in diameter, respectively). The dependence of absorption, luminescence spectra and optical losses at the wavelength of 1 µm on growth temperature and melt-solution composition was studied. We demonstrated that Cr4+ centers have been implemented in epitaxial films and these films may be used as passive Q-switches for laser systems. [ABSTRACT FROM AUTHOR]

Experimental and computational data for determination of temperature profile in the region of crystalline laser disk pumping are presented. The analytical relations obtained link the values of temperature, pumping spot radius, and disk thickness and allow optimization of these parameters in the choice of laser construction. Good agreement between computational and experimental results is demonstrated on an example of an Nd:YVO4 crystal disk active element. [ABSTRACT FROM AUTHOR]