Optimizing a lab-on-a-fiber optic device for trace TNT explosive detection

Based on the lab-on-a-fiber (LOF) concept we proposed before, we further optimize its architecture while preserving its capability in fluorescent signal collection and excitation stray light rejection. This LOF device is a short fiber taper with a TNT sensory film overlay at one end of a 400 jam core fiber which is approximately 50 mm long. The optimized LOF also lowers the system cost, eases the fiber replacement and maintenance, which are enabled by a reusable 3-leg bifurcated fiber bundle with SMA connectors to connect LOF, an excitation light source and a spectrometer. This LOF device occupies only a phi 0.4 mm x 1 mm space.