Robust Mid-IR Optical Fibers for Extreme Environments

ABSTRACT: Chalcogenide glass fibers are commercially available and are used for delivery of mid-infrared wavelengths (1.5um to 6.5um). These fibers allow compact, robust and low-weight laser platforms designs. Laser systems in high-power and high-stress environments find their reliability and performance limited due to free-space optical components. Free-space components suffer from vibration and thermal issues that can be eliminated by employing optical fibers as means of beam guidance throughout the platform. Current state-of-the-art chalcogenide fiber production yields fibers with good optical qualities and consistent mechanical properties. However, chalcogenide fiber mechanical strength and optical transmission could be improved significantly by reducing impurities introduced during glass and fiber fabrication. The proposed effort will demonstrate the feasibility of developing materials improvements to current chalcogenide glass and fiber fabrication processes that will increase fiber strength and decrease transmission losses. These novel processes will surpass current state-of-the-art yielding chalcogenide fibers with improved mechanical and optical properties capable of handling high-power and high-stress environments typical for IRCM laser system applications. Chalcogenide fibers could replace free-space optical components in military, industrial and medical applications in need of better performance and reliability under high-stress, high-power environments. ; BENEFIT: Development of chalcogenide fibers capable of low-loss (20kpsi) and capable of working under harsh environments is of great benefit for military applications, especially for next generation infrared countermeasure (IRCM) laser systems. These fibers would be able to replace free-space optical components currently employed on laser platforms. These platforms find their reliability and performance limited under high-stress and high-power environments, due to its free-space components. Chalcogenide fibers allow a platform with improved reliability and performance, immune to vibrations present in high-stress environments, capable of handling high-powers which effectively removes the limitations currently set by free-space optics; while also offering platforms with reduced cost, weight and size. Additionally, industrial, medical and other military applications would benefit from the improved chalcogenide fibers. Applications such as: chemical sensing, laser surgery, long-range detection, etc.; are some examples. Also, these fibers can be utilized to develop fiber-optics devices for mid-infrared lasers. Quantum cascade lasers are an attractive laser source covering the whole mid-infrared region, chalcogenide fibers with a transmission window covering the whole mid-infrared would be of great benefit for such laser sources.