Chapter 7 - OSL measurement technology

Abstract

This chapter explains the technology of optically stimulated luminescence (OSL) measurement. The basis for OSL measurements is the stimulation of an irradiated sample with a light source providing a selected wavelength or wavelengths and the monitoring of the emission from the sample at a different wavelength using a sensitive detector (e.g., a photomultiplier (PM) tube). Different modes of stimulation can be used, for example, continuous wave-OSL (CWOSL), linearly modulated OSL (LM-OSL), and pulsed OSL (POSL). The growing industrial interest in ultra-bright LEDs as light indicators (e.g., from automobile manufacturers) may soon make visible LEDs commercially available with a greater variety of emission wavelengths and substantially higher emission power than is available today. These LEDs should provide sufficient power to be considered a real alternative to lasers and powerful incandescent lamps as light sources in OSL. Further developments in, and investigations of, luminescence imaging systems for obtaining spatially resolved thermoluminescence (TL) and OSL signals from multi-mineral samples are also foreseen. These systems give rapid and valuable information about the mineralogy of the sample and enable individual analysis of luminescence signals from single grains of a sample. This has the potential to avoid the cumbersome mechanical and chemical separation processes presently required. Thus, it is possible to map solid surfaces containing grains with different OSL sensitivities and different doses.