Chalcogenide Infrared Fiber Manufacturing Technology

Chalcogenide glass fibers are extensively used for delivery of mid-infrared (2-5 micron) laser wavelengths. They are needed for development of next-generation Directed InfraRed CounterMeasure (DIRCM) systems. Replacing the bulky free-space delivery system with fiber will reduce the weight and size of these systems enabling the installation in vehicle and aircraft with stringent weight and size requirements. These fibers have industrial uses, such as remote sensing, environmental monitoring, and spectroscopy. Chalcogenide fibers, however, lose more than 50% transmission beyond ~ 10 m and suffer from low mechanical strength barely passing the 15 kpsi tensile proof test. The main contributors to the loss level and mechanical strength are impurities in the glass, and contaminant exposure and imperfections introduced during fiber draw. Therefore, good fiber transmission over 10 meters and improved mechanical properties require a novel manufacturing process. The feasibility of developing a prototype manufacturing process that is capable of producing chalcogenide glass fibers with low-loss (< 0.15 dB/m) and high mechanical strength (proof tested with > 20 kpsi) was demonstrated in phase I. Major impurities that contribute to the loss and strength were identified. Modifications to current manufacturing processes were suggested and are currently being implemented to reduce these impurities.