To fight against the explosives-related threats in defense and homeland security applications, a smarter sensing device
that not only detects but differentiates multiple true threats from false positives caused by environmental interferents is
essential. A new optical detection system is proposed to address these issues by using the temporal and spectroscopic
information generated by the surface plasmon coupling emission (SPCE) effect. Innovative SPCE optics have been
designed using Zemax software to project the fluorescence signal into clear "rainbow rings" on a CCD with subnanometer
wavelength resolution. The spectroscopic change of the fluorescence signal and the time history of such
changes due to the presence of a certain explosive analyte are unique and can be used to identify explosives. Thanks to
high optical efficiency, reporter depositions as small as 160-μm in diameter can generate a sufficient signal, allowing a
dense array of different reporters to be interrogated with wavelength multiplexing and detect a wide range of explosives.
We have demonstrated detection and classification of explosives, such as TNT, NT, NM, RDX, PETN, and AN, with
two sensing materials in a prototype.