|Coherent Mid-Infrared Fiber Source Technology
|Sensors & Electronics Technology|
fiber lasers, infrared countermeasures, Infrared lasers, remote sensing
Mid-infrared laser technology is critical to the development of active sources for defeating a growing spectrum of heat seeking missiles, as well as for remote sensing of targets and threats, and increasingly, for active imaging. Source components must tolerate environmental changes, and fit into platforms from large naval vessels to combat aircraft and helicopters. The optical confinement and inherent geometry of fiber lasers give them distinct advantages over conventional bulk solid state lasers for these applications. SET-170, recently ended, pursued advances in fiber-based sources operating beyond 3 µm, including fibers for both direct lasing and nonlinear frequency conversion. Results of the RTG combined with ongoing developments in this rapidly evolving field suggest directions for further research that will leverage the combined resources and expertise of participating nations to demonstrate advanced fiber-based sources that are efficient, compact, and spectrally suited to critical military applications.
The objective is to improve the wavelength versatility, efficiency, power/energy, ruggedness and simplicity of fiber-based coherent sources, through collaboration involving leading researchers in participating nations, focusing on the technical areas listed in III. This collaboration will build upon the spectroscopic, modelling, and device results obtained under SET-170, incorporating other relevant developments in the field. Specific goals will include: demonstrating the practicality of rare-earth-doped fibers for military applications; increasing the output power and IR spectral coverage of supercontinuum sources; and addressing the need for broadly tunable sources for IR countermeasures. While the focus of the new Task Group, like its predecessor, will be on exploiting the inherent advantages of optical fibers in the 3-5 µm region and beyond, the scope will be broadened to include development of fiber pump sources operating at shorter wavelengths, and the integration of fibers with waveguide or bulk devices to produce hybrid systems with enhanced mid-IR properties and performance.
The specific topical areas can be grouped based on the type of source they produce:
1. Fixed-wavelength sources based on rare-earth-doped fibers
2. Broadly tunable sources based on transition-metal-doped fibers, fiber-pumped waveguide or bulk nonlinear (χ(2)) devices, or guided wave OPO/OPA/Raman processes
3. Highly broadband sources based on supercontinuum generation in infrared fibers.