Mid-infrared optical fiber Fourier transform infrared spectrometer

The need for small, robust, and highly selective sensors, for both military and homeland security requirements, is driving the development of portable detectors for hazardous materials. Infrared spectroscopy exhibits high selectivity because the infrared vibrational transitions correlate to the molecular structure and functional groups within the molecule. Small FTIR systems exist as COTS items; however, these systems still require precise moving components to generate the interferogram. A more desirable approach is to build a solid state system with no precision moving parts as required by a typical moving mirror interferometer. This work will describe the design aspects of an optical fiber based mid-infrared FTIR, and focus specifically on the stateof- the-art mid-infrared transmitting optical fibers and the use of an optical fiber supercontinuum source for efficient coupling of light into the system.