Mode-Filtered Fiber Amplifier Technology Wins R&D 100 Award
Lohja, Finland September 13, 2007
LIEKKI Corporation, a leading supplier of highly doped fibers and optical engine modules for fiber laser and amplifier applications, has licensed and commercialized the mode-filtered fiber amplifier technology recognized with the R&D 100 Award.
Sandia National Laboratories and the Naval Research Laboratory have been honored with one of this year's R&D 100 Awards for their development of the mode-filtered fiber amplifier technology. The inventors are Jeffrey Koplow and Dahv Kliner, Sandia National Laboratories, and Lew Goldberg, Naval Research Laboratory. Mode-filtering allows fiber amplifiers to scale to very high output powers, revolutionizing the laser market.
The R&D 100 Awards, presented every year since 1962, recognize the most promising new products, processes, materials, or software developed throughout the world and introduced to the market. The awards are based on each achievement's technical significance, uniqueness, and usefulness compared to competing projects and technologies.
The award-winning mode-filtered fiber amplifier technology increases the power scaling limits of fiber amplifiers by more than 100 times, enabling the production of multiple kilowatts of output power in a single-mode beam. This advance opens the door to use fiber amplifiers in many real-world applications, such as materials processing, remote sensing, nonlinear frequency conversion, and more. Fiber-based devices have substantial advantages over competing technologies, including far superior beam quality, wavelength flexibility, electrical efficiency, waste heat generation, maintenance requirements, and package size.
Sandia's award application cites LIEKKI as one of the licensees who produce commercial products based on the mode-filtered fiber amplifier technology. Sandia has previously, at Photonics West 2006, published results on high-peak-power, >1.2 MW, pulsed fiber amplifiers using LIEKKI™ fiber and this invention.
The mode-filtered fiber amplifier technology is notable for its simplicity. High-power amplifier fibers with large core sizes allow many “modes” of light to propagate through them, resulting in a relatively unfocused beam. By strategically coiling the fiber around a chosen radius, it is possible to induce bend loss, stripping out high-order modes while allowing the fundamental mode to propagate through the fiber unimpeded. This mode filtering is achieved with no deleterious side effects upon the other laser performance characteristics. It essentially converts what would have been an undesirable multimode fiber amplifier into a much more desirable single-mode amplifier, while retaining the benefit of using an optical fiber with a large core size.