S. G. Lunter

Properties of neodymium-doped aluminophosphate laser glasses

Neodymium-doped glass lasers for obtaining high average output require the development of high-efficiency technological compositions of laser glasses, combining superior thermomechanical qualities with good laser and optical properties. Intermediate-power lasers, with neodymium-doped glass as the active element, have limited energy capabilities because of the temperature gradient that is induced in the glass during operation and causes the active element to fracture. In order to compare the thermomechanical properties of laser glasses with different compositions we calculate the quality factor (RT*) [I] for the given active material from the formula

Large disc-shaped active elements made from neodymium phosphate glass elements made from neodymium phosphate glass

A technology has been developed for the production of large active elements made from KGSS 0180/35 neodymium phosphate glass (with a neodymium ion concentration of NNd53.5 x1020cm-3), iintended for powerful pulsed lasers with high output radiation energy. The neodymium glasses were melted using a two-stage or single-stage process with high-purity reagents in crucibles made from dispersion-strengthened platinum or a newly developed highstrength cristobalite refractory, which, along with other process methods, makes it possible to obtain glass that contains no metallic platinum inclusions. The main elements of the process for synthesizing neodymium glass are deep oxidation of the melt with dry oxygen in order to convert traces of platinum and iron to higher valence states and simultaneously eliminate hydroxyl group impurities, as well as the use of a nonplatinum refractory to fabricate the glassware. The resulting glasses are characterized by high optical homogeneity, high luminescence lifetime of the neodymium ( t~300 us), radiation strength to 33 J/cm2 when the exciting pulse width is 3?4 ns, and a nonactive absorption coefficient at the lasing wavelength of about 0.0015 cm-1. The required high-quality surface processing of the active elements is provided by fine annealing of the blanks and by using grinding?polishing equipment with program control.

Optimizing the dopant concentration in neodymium and erbium glasses for pulsed-periodic lasers with lamp pumping

Spectroscopic and lasing studies are used as a basis for establishing the optimum dopant concentration in neodymium and erbium glasses to ensure that they are uniformly pumped and to maximize the energy efficiency.

Efficiency of absorption of light from a xenon pump lamp in neodymium glass

A calculation was performed on the basis of the absorption spectra of Nd3+ in commercial glasses and in modeled matrices. This made it possible to compare the energy absorbed in the active element, the energy converted into stimulated radiation, and the heat energy losses as a function of the thickness of the absorbing layer of glass. The calculation was made taking into account the spectral distribution of the energy of the pump lamp radiation. A comparison was made of the role played by individual parts of the Nd3+ absorption spectrum in the process of the assimilation of the pump light by the energy activator. An estimate was made of the energy of the heat losses due to nonactive absorption by the antisolarizers and the matrix in commercial glasses GLS22, GLS32, and GLS34. Dependences making it possible to optimize the spectral position of the absorption edge of a filter, cutting off the ineffective radiation from the pump lamp, were obtained.