In this paper, recent works of buried chemical detection system by stimulating and enhancing spectroscopic
signatures with multi-frequency excitations are discussed. In this detection system, those multiple excitations,
including DC electric field, microwave, CO2 laser illumination and infrared radiation, are utilized and each of
them plays a unique role. The Microwave could effectively increase the buried chemicals' evaporation rate from
the source. The gradient DC electric field, generated by a Van De Graaff generator, not only serves as a vapor
accelerator for efficiently expediting the transportation process of the vapor release from the buried chemicals,
but also acts as a vapor concentrator for increasing the chemical concentrations in the detection area, which
enables the trace level chemical detection. Similarly, CO2 laser illumination, which behaves as another type
vapor accelerator, could also help to release the vapors adsorbed on the soil surface to the air rapidly. Finally, the
stimulated and enhanced vapors released into the air are detected by the infrared (IR) spectroscopic fingerprints.
Our theoretical and experimental results demonstrate that more than 20-fold increase of detection signal can be
achieved by using those proposed technology.