Progress towards the development of intrinsically low-nonlinearity and low-loss optical fibers for high-energy laser applications is outlined. Owing to the high optical intensities and relatively long interaction lengths in high-energy fiber lasers systems, a wide range of deleterious, power-limiting processes can be excited, all of which require careful management. Here, a materials-based approach is taken to enhance the power available from such systems. Specifically discussed in this context are: 1) decreasing the strength of Brillouin scattering, mainly through the reduction of glass photoelastic constant p12; 2) the reduction of the strength of Raman scattering by taking advantage of glass disorder and the judicious use low-Raman-gain additives; 3) elevation of the threshold for the onset of thermal mode instabilities through a reduction in the thermo-optic coefficient, dn/dT; and 4) all while not adversely impacting the relatively low value of n2 afforded by glasses comprised mainly of silica. The ultimate goal of this work is the development of active fibers with Brillouin gain coefficients reduced by 15 dB, Raman gain coefficients reduced by 3 dB, and dn/dT values reduced by 3 dB, with background losses well below 100 dB/km all in a single fiber. The current state of this effort will be discussed and the outlook for the development of such a fiber will be described.
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