SBIR-STTR Award

Laser-induced breakdown spectroscopy (LIBS) has shown great promise for applications in chemical, biological and explosive (CBE) sensing [1-12]. Nearly all previous LIBS experiments were limited to measurements in the UV-VIS and NIR. However, molecules exhibit spectroscopic signatures in the MIR to FIR wavelength region from vibrational and rotational transitions. Therefore, an extension of LIBS to the IR region promises to provide information which can augment results from conventional UV-VIS LIBS measurements. Recently, we have demonstrated the first infrared LIBS emission signatures in the 3-5 um spectral region [13-16]. By adding the feature of laser energy control it can operate both as LIBS and Laser Induced Thermal Emission (LITE) technique/system. We propose a detailed study of IR LITE/LIBS in 1-12 um range for potential applications in CBE sensing. We will systematically irradiate CBE species (and related materials) with a laser at progressive energies and parameter settings to yield evaporation/desorption/vaporization or ablation, and capture the IR spectra of emitted photons. Particular attention will be noted for point (short range) and standoff dual use utility. We will develop a breadboard system and outline a roadmap for a field portable instrument. We will also develop a signature library from selected biological and chemical solid-state materials.

Keywords:
Laser-Induced Breakdown Spectroscopy Libs, Laser-Induced Thermal Emission (Lite), Chemical, Biological And Explosives (Cbe), Standoff Detection, Cbe Sensing

There is a current need for an active standoff system that can detect and classify surfaces that have been contaminated with chemical, biological and explosive (CBE) materials. Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Induced Thermal Emission (LITE) has shown great promise for detection of such contaminants. In Phase I of this program we, for the first time, have demonstrated generation and detection of MWIR & LWIR LIBS and LITE signatures from explosive stimulants and we presented the roadmap to developing a packaged, field portable IR LITE/LIBS unit. In Phase II of this work, we will improve and optimize the LITE system by using a sensitive, linear array detector (as opposed to the single element point detector that was used in Phase I.) Use of linear array detector will allow faster acquisition and a smaller area/quantity sample with no special sample preparation. Moreover, the proposed system will be capable of threat detection in the presence of interfering materials. We will develop an IR LIBS/LITE signature library (2-12 mm) for selected chemical, biological, and energetic solid-state simulant materials. At the conclusion of the Phase II work, we will deliver a packaged IR LITE/LIBS unit capable of standoff detection of CBE materials.

Keywords:
Laser-Induced Thermal Emission Spectroscopy (Lite), Long Wavelength Infrared (Lwir) Libs, Mid-Infrar