Advantages and limitations of stimulation with band shape modulation in OSL measurements

Highlights: • OSL process can be controlled by the modulation of the stimulation band shape. • Comparison of BSM-OSL with CW-OSL and LM-OSL methods by OSL computer simulations. • The lower stimulation energy results in better separation of diverse OSL components. -- Abstract: Inducing changes in the optical cross-section (OCS) can be used to control the OSL process in order to improve the separation of OSL signals originating from different traps. Two methods were intensively studied earlier, one using continuous changes in stimulation energy (the variable energy of stimulation OSL, VES-OSL) and the other using the linear heating of a sample (the thermally modulated OSL, TM-OSL). These methods require either an advanced measuring system with a strong tunable light source or heating, which in some cases can be problematic (TM-OSL). It turns out that changes in the shape of the spectral band used for stimulation can also be used for advantageous control of the OSL process. Such a method, called band shape modulation OSL (BSM-OSL), can be realized technically in a very simple way by applying at least two sources of light with various spectral bands. Here, the ability of the BSM-OSL method to separate the OSL signal related to different traps is tested by computer modeling for a wide range of trap parameters, and then compared with the same capability of two previously used methods: CW-OSL and LM-OSL.