The invention provides methods, compositions, and apparatus for performing sensitive detection of analytes, such as biological macromolecules and other analytes, by labeling a probe molecule with an up-converting label The up-converting label absorbs radiation from an illumination source and emits radiation at one or more higher frequencies, providing enhanced signal-to-noise ratio and the essential elimination of background sample autofluorescence The methods, compositions, and apparatus are suitable for the sensitive detection of multiple analytes and for various clinical and environmental sampling techniques

Up-converting reporters for biological and other assays using laser excitation techniques

Modifying the solar spectrum to enhance silicon solar cell efficiency—An overview of available materials

Upconversion processes in coupled ion systems

The upconversion fluorescences near 0.55 and 0.66 μm and Stokes fluorescences near 0.98 and 2.72 μm were measured for Er3+-doped aluminate, gallate and several other glasses under infrared ation into the 4 I 9 2 level. It was found that the quantum efficiencies of emissions from a given level, except the 4 I 13 2 level, increased in the order of decreasing phonon energies of the glass hosts. The fluorescence originating from the 4 I 13 2 level and its quantum efficiency are not dependent upon the phonon energies of glass hosts, due to influences of the energy transfer upconversion and excited state absorption from the 4 I 13 2 level. Moreover this fluorescence is closely related to the 4 I 11 2 lifetimes, in which the stronger fluorescence can be observed in a glass which has a shorter 4 I 11 2 lifetime. The green upconversion fluorescence originating from the 4 S 3 2 level mainly results from the excited state absorption from the 4 I 13 2 level and the red upconversion fluorescence coming from the 4 I 9 2 level mainly generates from the energy transfer upconversion through the 4 I 13 2 level for Er3+-doped aluminate and gallate glasses.

Spectroscopic properties and mechanisms of excited state absorption and energy transfer upconversion for Er3+-doped glasses

To develop NaYF4 as bulk luminescence material, transparent glass ceramics containing Er3+:  NaYF4 nanocrystals were fabricated for the first time, and the influences of heat-treatment temperature and Er3+ doping level on their upconversion luminescence were investigated. With increasing heating temperature, the upconversion intensity enhanced accordingly, attributing to the incorporation of more Er3+ into the grown NaYF4. Notably, when the heating temperature reached 650 °C, the upconversion intensity augmented drastically due to the occurrence of phase transition from the cubic NaYF4 to the hexagonal one. Interestingly, for the samples heat-treated at 620 °C, when the Er3+ doping level was increased from 0.05 to 2.0 mol %, the upconversion emission was whole-range tunable from monochromatic green to approximately monochromatic red, which could be mainly attributed to the cross-relaxation between Er3+ ions. The excellent optical properties and its convenient, low-cost synthesis of the present glass ceram...

Tunable Red-Green Upconversion Luminescence in Novel Transparent Glass Ceramics Containing Er: NaYF4 Nanocrystals

An active optical device comprises a glass, waveguiding structure disposed on a substantially planar principal surface of a substrate. The structure includes a silica-based, erbium-doped active core. The active core has an absolute erbium concentration of at least about 0.5×1020 atoms per cubic centimeter, and a radiative lifetime of the erbium lasing level of at least about 5 milliseconds. The active core does not contain significant amounts of alkali metals or alkaline earth metals but does contain at least two modifier metals. Also disclosed is a method for forming an active optical device, including the step of depositing an erbium-doped active core by sputtering.

Erbium-doped planar optical device

Intense visible emission in the red, green, and blue has been observed from infrared to visible multiphoton Y1−xErxF3 upconversion phosphors pumped with 1.5‐μm radiation from InGaAsP‐laser sources. With 0.01<x<0.2, the dominant emission is in the green corresponding to transitions from the 4S3/2 level of Er3+. The addition of Tm3+ in the 0.001–0.02 range preferentially quenches the emission from the higher‐energy Er3+ levels resulting in a red visible emission originating on the Er3+ 4F9/2 level. The phosphors are useful visible monitors of focused 1.5‐μm semiconductor laser and unfocused F‐center laser radiation. The unexpectedly high brightness in the visible may be attributed to thermal equilibration, where the excitation is trapped in the higher lying states after each upconversion step.

W. H. Grodkiewicz

Papers

Erbium-doped planar optical device

1.5‐μm infrared excitation of visible luminescent in Y1−xErxF3 and Y1−x−yErxTmyF3 via resonant‐energy transfer

Minimum Loss Projections for Oxide and Halide Glasses

New Arsenate Glasses

Tantalum-aluminium oxid Beschichtung für Halbleitervorrichtungen