All-Fiber Infrared Raman Laser

In the Phase II program we will demonstrate a breadboard device of an innovative all-fiber infrared (IR) laser operating at selectable wavelengths in the 1.5 to 12 micron spectral region based on Stimulated Raman Scattering of hydrogen gas in an IR hollow-core photonic band-gap (PBG) fiber. The Raman laser is pumped by commercially available fiber laser at near-infrared wavelength. Its wavelength can be selectable by tuning the pump laserwavelength. The PBG fiber is fabricated using a new IR material developed in Phase I, which is highly transparent in the broadband infrared region. Confining hydrogen and pump light together in the hollow core of the PBG fiber can lead to much higher Raman laser conversion efficiency and low threshold. The all-fiber laser structure is compact and robust. No free-space optical components are used. It is insensitive to environmental changes in temperature, pressure, humidity, and vibration. The laser can be used for infrared countermeasures to the next generation of heat seeking missiles and for high-resolution, long-range target identification remote sensing of biological or chemical agents. In Phase II, we will produce the PBG fiber and build a prototype of the all-fiber infrared Raman laser. BENEFIT: The all-fiber, robust and compact infrared Raman fiber lasers can be used as infrared countermeasures (IRCM) for defense against heat seeking missiles or man-portable air defense system. Illumination, targeting, secure communications and sensing are also important military applications for the fiber lasers. Infrared lasers are of great interest for a wide range of scientific and technological applications from spectroscopy and frequency metrology to information technology, industrial process control, photochemistry, photobiology and photomedicine, contamination control, atmospheric chemistry, imaging as well as rapid detection of explosives, chemical and biological agents.