Unusual Luminescence from Crystals ContainingEu2+

Luminescence properties of impurity-doped semiconductor nanoparticles

“…Since the first report of unusual luminescence in impurity doped powders [39,40], it has been expected that impurity-doped nanoparticles and microparticles show unique and fascinating optical properties. In particular, the report on Mn 2+ -doped ZnS nanoparticles (the high PL efficiency and the short PL lifetime) stimulated considerable efforts [41].…”

The role of polymers in random lasing

“…The pioneering experiments on RL phenomenon were conducted in the 1970s and 1980s. It is worth mentioning articles written by Varsanyi, Fork et al, Fork and Taylor, Nikitenko et al, and Markushev et al, which may be acknowledged as trailblazing experimental works in the field of RL. The aforementioned authors succeeded in obtaining laser action in powdered lanthanide based materials and ZnO powders, which are nowadays known as the powder lasers or following Wiersma and Lagendijk as random lasers.…”

“…Recently it has been proven that many different types of materials can show lasing in the process of RL. Powdered inorganic and organic crystals, single crystals with morphological defects, simple mixture of laser dye solution with scattering particles (also referred to as laser paint), liquid crystalline materials as well as different types of polymers are able to generate laser light without any advanced technology of their fabrication, which is highly advantageous . What is interesting from a theoretical point of view is that disordered systems can also supply coherent feedback for laser emission, which was initially discovered and studied by Cao et al showing that interference effects cannot be neglected at all and different types of light propagation distribution and mechanisms of light localization have to be considered in order to describe the RL phenomenon properly .…”

Lasers with Nonresonant Feedback and Laserlike Emission from Powders: Early Ideas and Experiments

“…It was proposed that miniature light sources, powder lasers, could find applications in integrated circuit networks [24]. In the 1970s, Fork et al observed unusual optical properties in microcrystals of different luminophosphors containing Eu 2+ [25][26][27][28]. The anomalously efficient and fast emission occurred in single microcrystals, the dimensions of which were on the order of several optical wavelengths, λ ≈ 0.37 µm.…”

“…The focus of this book is primarily on the emission enhancements occurring in ensembles of excited particles or random lasers. However, as evidenced by the experiments of Varsanyi [24] and Fork [25][26][27], stimulated emission and unusual optical effects, which remotely resemble stimulated emission, can also take place in individual particles constituting ensembles. The discovery and study of powder (random) lasers was done in parallel with the development of other micron-scale sources of laser emission [32], including microchip lasers [33,34], microsphere lasers [35][36][37], and microdisk lasers [37].…”