A two-fiber spectroscopic system was assembled using a simple diode array spectrometer (Ocean Optics Inc., USA). The bandwidth of each spectral bin was 2 nm. The source was a white light source (Ocean Optics Inc., USA). The system operated over the 380-820 nm range.
Two probes were built.
One probe was a pair of optical fibers inserted into two hollow stainless steel tubes, terminating at a rod that was polished at 45 degrees so as to act as a mirror. This mirror deflected photons from the source fiber out of a hole in the tube (source) and deflected collected photons through the hold into the collector fiber (collector).
The other probe was a set of 7 source fibers surrounding a central collection fiber. The fibers were 200 microns in diameter with 200 microns center-to-center spacing between fibers.
