Investigation on rare earth ion doped solid state loser hosts Single crystals and transparent ceramics

Abstract

Solid state lasers are lasers that are based on the gain media which are solids such as crystalline materials or glasses doped with rare-earth or transition-metal ions. Many favorable characteristics such as chemical stability, mechanical durability, and long operational lifetime have put these laser systems among the most preferred candidates for a wide range of applications. Investigations on new laser materials with various rare earth ions are always of interest towards the generation of solid state lasers for specific applications. In the present investigation, KGW single crystals were grown by top seeded solution growth method with dysprosium and erbium ions as dopants at different concentrations. In addition to that, spectroscopic investigations have been carried out on CaF2 and YAG transparent ceramics doped with rare earth ions. Single crystal X-ray diffraction analysis confirmed the monoclinic structure with a slight variation in the lattice constant values compared to the pure crystal. Raman studies reveal a major role played by the interstitial fluorine ions on the vibrational properties. Integrating sphere and a 407 nm laser diode were used to find the quantum efficiency values of the samples. The efficiency value was around 62% for 0.1% Eu:CaF2 whereas the values were 4.9 and 26.48% for 3 and 10% Eu doped ceramics. The increase in emission intensity around 1.06 and#61535;m is due to the energy transfer from Ce3+ to Nd3+ ions. The results confirm that Nd:Ce:YAG can be a new material for solar pumped lasers. Effect of chromium ion on Nd:YAG transparent ceramics has been investigated spectroscopically. Under an excitation of 801 nm, emission spectra showed the Nd3+ emission peaks. Increase in Cr concentration shows the decrease in intensity corresponding to Nd3+ ions. Under 407 nm excitation, the emission intensity of Nd3+ peaks increase with an increase in Cr concentration. The lasing oscillation was in pulse mode, and mainly attributed to the self Q-switched operation because of presence of some traces of Cr4+