Direct and chemically-mediated absorption spectroscopy using optical fiber instrumentation

This paper shows various applications of optical fiber sensors to absorption spectroscopy. Sensors for the monitoring of chromium in sewage water and for the colorimetry of gasoline samples are presented together with sensors for radiation dosimetry in radiotherapy and for lighting control in museum environments. In all these sensors, a combination of broadband and multi-band spectral measurements are collected using the same custom instrumentation unit consisting of LED light sources and an optical fiber microspectrometer. Extensions of the unit to implement other sensors making use of visible spectral range are discussed. The custom instrumentation implemented to address these sensors is their key unifying feature. It opens the possibility of addressing other sensors making use of absorption-based optrodes which present an analyte-modulated absorption spectrum in the visible spectral range.