High Efficiency Gain Media for Eye-Safer 1.55 æm Ultrafast Fiber Amplifiers Navy STTR FY2010.A Sol No.: Navy STTR FY2010.A Topic No.: N10A-T012 Topic Title: High Efficiency Gain Media for Eye-Safer 1.55 æm Ultrafast Fiber Amplifiers Proposal No.: N10A-012-0689 Firm: Kapteyn-Murnane Laboratories Inc. 1855 South 57th Court Boulder, Colorado 80301 Contact: Daisy Raymondson Phone: (303) 544-9068 Web Site: www.kmlabs.com Abstract: We propose to design a high average power Er:Fiber ultrafast laser system which is pumped at 14xxnm, and at the same time solve other problems related to ultrashort pulses in fiber lasers. The advantage of using 14xxnm pumping is the reduction of the standard quantum defect from 37% to 5%, thus greatly reducing the thermal load on the system, which makes it inherently more efficient. We also intend to construct an Er:fiber oscillator based on a new potentially rugged modelocking mechanism, which includes the positive dispersion regime known to reduce adverse non-linear effects in the gain medium. From this, and research into new fiber materials (Nufern), we will design a full amplified ultrafast laser system for implementation in Phase II. Benefits: The potential efficiency gains available from pumping Er-doped fiber lasers with 14xx nm instead of the current standard 980 nm should find widespread applications. Reduced power requirements will improve portability of high-power eye-safe military rangefinders. In fields such as manufacturing, robust, high-efficiency directly diode-pumped fiber lasers for micromachining will allow significant cost savings. This technology will also impact several areas of basic and applied research. While a smaller market, the research community has a disproportionate impact on the development of future technologies. Research in ultrafast chemistry increasingly requires short ~100 fs pulses in the 1.5 micron wavelength range. Robust, turn-key lasers filling these requirements at higher average power will allow previously inaccessible experiments. In the field of extreme nonlinear optics, a highly efficient fiber amplifier could be an alternative candidate as a front-end for ultrafast x-ray generation through high-order harmonic generation. While the pulse durations available from fiber amplifiers do not currently rival research grade ti:sapphire lasers, ti:sapphire amplifiers are expensive (~$300k) and typically require a laboratory-type environment. A fiber amplifier combined with additional spectral broadening and pulse compression would have potential advantages of cost, compactness and reliability benefitting, for example, a manufacturing environment needing soft x-rays for semiconductor mask inspection. Return