The beautiful colours of many inorganic compounds, including minerals and gemstones, as
well as the mysterious cold light of luminescence emitted by these materials, have attracted …

The optical absorption and fluorescence spectra of two spinels, ZnAl 2 O 4 :Cr 3+ and MgAl
2 O 4 :Cr 3+ have been measured at various temperatures between 2K and room …

In this chapter we present an outline of the optical spectroscopy of ions and molecules in
solids which will serve as a background for the later chapters. We adopt a general approach …

The energy levels of an impurity ion in a solid are in general shifted and broadened by thermal
vibrations of the host lattice. A study of these effects in a simple system can lead to some …

The radiative efficiency of YAG: Cr 3+ is known to increase rapidly with increasing
temperature. This increase is larger than that expected purely on the basis of the increase with …

The transfer of energy from single chromium ions to closely coupled pairs of chromium ions
in ruby has been investigated. Ruby samples whose concentrations ranged from 0.003 to 1.0…

The optical spectroscopy of nickel-doped LiGa 5 O 8 is presented. Absorption and luminescence
measurements taken over a wide temperature range indicate that the dopant nickel ion …

The luminescence spectrum of MgO: Cr 3+ is characterized by a series of sharp features at
around 7000 Å and a broad band which stretches from about 7000 Å to 1 μm. The nature of …

Information about the behavior of traps in a luminescent material is usually derived by fitting
the glow curves in the thermoluminescence spectrum of the material to a general formula. …

A luminescence study of the Y 3 Al 5 O 12 :Mn 4+ system is presented. Luminescence is
due to 2 E → 4 A 2 transitions on Mn 4+ ions which substitute for Al 3+ ions in distorted …