Photoluminescence Upconversion with the Fluorolog-QM

Upconversion is a very hot topic in fluorescence spectroscopy, with many exciting new applications, particularly for rare earth sciences. Upconverting materials exhibit a unique fluorescence anti-Stokes shift, which enables them to convert NIR wavelength excitation absorbance into visible shorter wavelength emissions (NIR to UV-VIS).

The upconversion process involves the sequential absorption of two photons and subsequent emission of a photon of a higher energy. The most efficient upconverters are trivalent lanthanide ions due to their wellshielded 4f and 5f electronic orbitals with reduced electronphonon coupling, which minimizes multi-phonon relaxation processes and increases the probability of upconversion involving their long-lived metastable states.

The research effort to design and characterize upconverting materials has been rapidly growing as numerous applications have emerged. These include designing efficient and inexpensive UV-VIS lasers, increasing solar cell efficiencies, biomedical imaging, drug delivery, optoelectronics et al.

The new Fluorolog-QM spectrofluorometers, due to their modularity and advanced software and a universal interface, are an ideal choice for studying multiple aspects of upconversion.