Optical fiber chemical sensor; Tapered core; Evanescent-wave (EW) absorption; Spectrophotometer; Attenuated total reflection (ATR) spectroscopy; Multimode optical fiber
A spectrophotometer has been developed using tapered core multimode optical fiber (PCS-600). It is based on the phenomenon
of evanescent wave absorption and is capable of identifying the chemical species having the absorption peaks in the visible region of the spectrum (400–700 nm). Aqueous dye solutions of different concentration in the pure and mixed form have been tried and detected. The experimental results obtained are discussed in the form of the possibility of using this system as a spectrophotometer.
A microprocessor based programmable kit for tapering the optical fiber with good precision and the detector system for the
output signal, designed and developed are also discussed.