Single Mode Hollow Core Waveguides for Long-Wave Infrared (LWIR) Lasers

Spectroscopy in the long-wave infrared (LWIR) wavelength region (8 to 12 µm) is useful for detecting trace chemical compounds, such as those indicative of weapons of mass destruction. To enable the development of field portable systems for anti-proliferation efforts, current spectroscopy systems need to be made more robust, convenient, and practical (e.g., miniaturized). Fiber optics that can operate in the LWIR region are a key enabling technology needed to improve the utility and effectiveness of such systems. However, such fibers must be able to deliver single-mode Gaussian beams with low loss in the LWIR region, which is a capability not currently available in typical IR fibers. Although chalcogenide glass fibers are effective for the mid-wave infrared (MWIR) wavelength range (3 to 8 µm), the transmission of chalcogenide glass fibers drops off rapidly for wavelengths above 9 µm. This project will develop hollow core waveguides that can transmit with minimal loss over the range from 8 to 12 µm. In Phase I, sample hollow waveguides will be designed and fabricated. The waveguides will be packaged with suitable protective jackets and connectors for ease of operation. Commercial Applications and other Benefits as described by the awardee:The new line of fiber optics would improve the utility and effectiveness of laser systems used to detect specific chemical compounds and molecules. Such improvements are important in efforts to prevent the proliferation of weapons of mass destruction. The technology also should find use in LWIR laser systems with applications ranging from chemical detection to laser surgery