Remote Near-IR Spectroscopy over an Optical Fiber with a Modified FT Spectrometer

A Fourier transform (FT) spectrometer was configured to measure near-infrared (near-IR) transmission spectra using 80 meters of a 206-μm optical fiber. The single-beam signal-to-noise ratio (S/N) was evaluated for the remote-sensing spectrometer for both Ge and InSb detectors. The instrumental performance was compared with that of the conventional FT spectrometer. The optical attenuation of several different fibers was measured and their possible use as transmission sensors was evaluated. Some advantages and implications of combining an FT spectrometer with optical-fiber sensor measurements are discussed.