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Ordered photonic structures (photonic crystals) have seen increasing interest in recent years due to their potential applications, which depend on fabrication technologies suitable for mass production. In this paper, we studied by light diffraction the order in photonic colloidal suspensions composed by core-shell (TiO2@Silica) nanoparticles suspended in ethanol and water solutions. Light diffraction measurements show order in these photonic colloidal suspensions, being stronger in ethanol compared with suspensions in water. Strong and long-range Coulomb interaction explains the order and correlation in the scatterers’ (TiO2@Silica) position, which favors significantly the interferential processes as localization of light.

Localization of light induced by correlation in the scatterers’ positions is achieved in an ordered photonic colloidal (TiO2@Silica) suspension. A strongly enhanced light-matter coupling is observed as the concentration of TiO2@Silica is increased above threshold.

While most common holographic methods of digital reconstruction are based on the convolution theory, for the ease in the mathematical approach, here we present an algorithm by a discretization of the Huygens-Fresnel integral from a Taylor series expansion to produce a bidimensional Fourier transform. Compared to the digital convolution method, the algorithm presented here is more concise and generates a reduction in processing time, since the Fourier transform appears only once in the discretization. Another advantage is associated with the production of results in the frequency domain, allowing the optical information to be obtained directly.

We report the production of double waveguides in Ge2O-PbO glasses doped with Nd3+ and silver nanoparticles by direct femtosecond laser writing. The beam quality measurements and refractive index change are presented.

Light diffraction measurements show order in photonic colloidal suspensions of scatterers. Strong and long-range Coulomb interaction explains the order and correlation in the scatterers’ (TiO2@Silica) position, which favors significantly the localization (interference) of light.

Random lasing is achieved in an ordered photonic colloidal (TiO2@Silica) suspension. Stronger correlation in the scatterers’ (TiO2@Silica) position, induced by stronger and longer-range Coulomb interaction improves light localization and random laser performance.

Understanding radiation damage to plastic is of great interest for possible construction applications. Two different plastics were gamma irradiated and their property changes were studied with micro-Raman spectroscopy, showing promising results in increasing its toughness.

The temporal behavior of TeO2-ZnO pellets of different Nd concentrations is studied. A shortening of the decay time is observed, indicating random laser behavior for this new laser material.

Here we report, to the best of our knowledge, the first diode-side-pumped continuous wave (cw) Nd3+:YVO4 self-Raman laser operating at 1176 nm. The compact cavity design is based on the total internal reflection of the laser beam at the pumped side of the Nd3+:YVO4 crystal. Configurations with a single bounce and a double bounce of the laser beam at the pumped faced have been characterized, providing a quasi-cw peak output power of more than 8 W (multimode) with an optical conversion efficiency of 11.5% and 3.7 W (TEM00) having an optical conversion efficiency of 5.4%, respectively. Cw output power of 1.8 W has been demonstrated.

Thulium has a large emission spectrum around 2.3 μm when used together with the YLF host. Since thulium concentration should be kept near 1 mol% to avoid cross‐relaxation, a highly concentrated sensitizer like ytterbium is used that can be diode‐pumped at 970 nm where high‐power diodes are available. The population mechanism for the upper laser level includes two energy transfer up‐conversion (ETU) processes from ytterbium to thulium. A third ETU process transfers population from the upper laser level. Moreover, back‐transfer from thulium upper laser level to ytterbium and thulium cross‐relaxation processes affect the efficiency of the 2.3 micrometer transition. Few data are available for these parameters in the literature. In this work we present experimental measurements of energy transfer parameters obtained using an OPO laser to excite selectively the energy levels. In order to establish the values and relevance of each parameter, we used a numerical, time resolved simulation which included the 5 energy levels of thulium and the 2 energy levels of ytterbium. A Yb:Tm:YLF crystal was end‐pumped by a 30 W fiber coupled diode laser emitting at 973 nm. With a maximum pump power of 18 W at the crystal, 650 mW of 2.3 micrometer laser radiation were achieved in a quasi‐continuous operation.

In this paper we demonstrate a tenfold pulse power enhancement by operating the Er:YLF laser at the strongly modulated relaxation oscillation region, at 3 μm wavelength. We obtained 1.2 W of average power for 250 μs pulse duration and up to 400 Hz of repetition rate for a 6.8 W, jitter free, single spike with nearly Gaussian temporal shape without any kind of intracavity Q‐switching device.