Mid-Infrared Fiber Bundle Imager

ABSTRACT: Infrared cameras for thermal imaging applications can operate between 2-14 microns. These cameras produce a thermal image using two-dimensional arrays of infrared detectors (such as ferroelectric detectors or microbolometers). Some critical military applications (such as spatial analysis of combustion processes in turbines combustors and afterburners) require the use of high spatial resolution infrared fiber bundle imagers (FBIs) due to the area of study being inaccessible to infrared cameras because of limited size and/or extreme environment. Coherent FBIs are commonly used in the visible and near infrared (0.4 to 1 microns) to remotely transfer images to cameras. Unfortunately, coherent FBIs for infrared imaging in the range of 1-12 microns are not commercially available. The work conducted during the SBIR Phase I demonstrated the feasibility of developing innovative FBIs that are inexpensive, flexible, rugged, high fiber-count bundles for use in the 1-12 microns. The FBI fabrication process will be perfected during Phase II effort to produce low-cost coherent infrared imaging fiber bundles that are 2-4 m in length, 1000-10,000 fibers in a 10 mm diameter bundle, minimum bend radius of 8 cm and attenuation less than 1 dB/m over the spectral range of 1 to 12 microns. BENEFIT: Fiber bundle imagers (FBIs) in the spectral range of 1-12 microns have many potential applications. The proposed FBI is targeted primarily at military applications for infrared viewing of harsh environment and/or in tight space where infrared camera cannot be used. The Air Force has a specific requirement for infrared viewing at turbine combustors and afterburners. The infrared FBI has other potential uses in military aircraft for surveillance, reconnaissance, and threat warning systems. Security Agencies (Federal Bureau of Investigation, Department of Homeland Security) and law enforcement officials could use the infrared FBI as a thermal fiber endoscope for covert surveillance from a safe distance to support hostage rescue, building surveillance, clearance, and search operations. Also the FBI can be made small enough to apply infrared spectroscopy to the study of human and other tissues. In-vivo biomedical imaging could differentiate spectra of cancerous tissues from those of corresponding non-cancerous tissues.