A -- LARGE FLATTENED MODE FIBER FOR FIBER LASERS

LAWRENCE LIVERMORE NATIONAL LABORATORY LICENSEE TO PRODUCE LARGE FLATTENED MODE FIBER FOR FIBER LASERS Announcement: Lawrence Livermore National Laboratory (LLNL), operated by the University of California under contract with the U.S. Department of Energy (DOE), wants to license the technology to build Large Flattened Mode (LFM) Fiber. Researchers at LLNL have developed a Large Flattened Mode (LFM) Fiber, which is particularly suited for use in fiber lasers. The invention permits the construction of higher power fiber lasers which retain good beam quality compared to lasers using traditional fiber. The fiber uses both refractive index profile engineering and gain profile engineering to create a fiber structure that only allows a preferred flat-topped mode to lase. For applications requiring high beam quality radiation from efficient, compact and rugged sources, diffraction limited fiber lasers are ideal, and to date have been demonstrated at average power levels exceeding 500 W. For conventional single-core step-index single-mode fibers, this power level represents the scaling limit because of nonlinear and laser damage considerations. Higher average powers would exceed nonlinear process thresholds or else damage the fiber due to the high intensity level in the fiber's core. Simply expanding the core dimensions of the fiber allows a straightforward power scaling. However, the enhanced power handling capability that results comes at the expense of beam quality, because of multiple transverse modes which lase simultaneously. Although this problem of multimode operation can be mitigated to some extent by appropriately designing the fiber's waveguide structure, limitations such as bend radius loss, sensitivity to thermally induced perturbations of the waveguide structure, and refractive index control, all become more stringent as the core diameter grows, limiting the extent to which the core diameter can be grown and still ensure single mode operation from the fiber. Our invention addresses some of these limitations and enables a new approach to single transverse mode operation of large mode area (LMA) fibers. This provides a route to high average powers possibly exceeding 1 kW from a single aperture in a Strehl-ratio-optimizing flat-topped output beam. LLNL would like to find a manufacturer of fiber or lasers who has an interest in licensing and commercializing this technology. Note: THIS IS NOT A PROCUREMENT. Companies interested in commercializing LLNL's Large Flattened Mode (LFM) Fiber should provide a written statement of interest, which includes the following: 1. Company Name and address. 2. The name, address, and telephone number of a point of contact. 3. A description of corporate expertise and facilities relevant to commercializing this technology. Written responses should be directed to: Lawrence Livermore National Laboratory Industrial Partnerships and Commercialization P.O. Box 808, L-795 Livermore, CA 94551-0808 Attention: FBO000026-03 Please provide your written statement within thirty (30) days from the date this announcement is published to ensure consideration of your interest in LLNL's Large Flattened Mode (LFM) Fiber technology.