Energy Transfer Studies in Tb-Yb Co-Doped Phosphate Glasses.

Detailed optical properties of Tb-Yb co-doped phosphate glasses were performed based on their emission spectra and decay measurements. Under blue excitation of Tb at 488 nm, the intensity of Yb emissions gradually enhanced upon increasing the Yb content until 1 mol% indicated an energy transfer from Tb to Yb. Otherwise, under near infrared excitation of Yb at 980 nm, these glasses exhibit intense green luminescence, which led to cooperative sensitization of the D level of Tb ions.

Laser Refrigeration by an Ytterbium-Doped NaYF Microspinner.

Thermal control of liquids with high (micrometric) spatial resolution is required for advanced research such as single molecule/cell studies (where temperature is a key factor) or for the development of advanced microfluidic devices (based on the creation of thermal gradients at the microscale). Local and remote heating of liquids is easily achieved by focusing a laser beam with wavelength adjusted to absorption bands of the liquid medium or of the embedded colloidal absorbers. The opposite effect, that is highly localized cooling, is much more difficult to achieve.

Infrared-to-Visible Light Conversion in Er(3+) -Yb(3+) :Lu3 Ga5 O12 Nanogarnets.

Er(3+) -Yb(3+) co-doped Lu3 Ga5 O12 nanogarnets were prepared and characterized; their structural and luminescence properties were determined as a function of the Yb(3+) concentration. The morphology of the nanogarnets was studied by HRTEM. Under 488 nm excitation, the nanogarnets emit green, red, and near-infrared light.