Short-pulse fiber lasers have increasing impact in applications, owing to their practical benefits. The science that underlies performance increases is the control and exploitation of nonlinear processes that can otherwise limit pulse energy and duration. I will describe a new regime of ultrashort pulse amplification that addresses two main challenges of fiber lasers: 1) management of nonlinear processes that ordinarily distort pulses, and 2) generation of bandwidths much broader than the gain spectrum. In this amplification regime, 70-fold spectral broadening, to well beyond the gain-narrowing limit, can be accommodated while still generating clean compressed pulses. This new amplification regime is based on dynamic evolution of the gain spectrum as a degree of freedom: as a pulse experiences nonlinear spectral broadening, absorption and amplification actively reshape both the pulse and the gain spectrum itself. Our theoretical and experimental evidence suggests that a nonlinear attractor underlies the pulse evolution, which we refer to as gain-managed nonlinear amplification. We find that this new regime is the foundation of recently-developed high-performance fiber oscillators, which now reach peak power well above one megawatt. Finally, we will discuss how the pulse-gain propagation dynamics should simplify the design of high-performance sources of ultrashort pulses.

报告人简介 Frank Wise received a BS in Engineering Physics from Princeton University, an MS in Electrical Engineering from the University of California at Berkeley, and a PhD in Applied Physics from Cornell University. Before PhD studies, he worked on advanced integrated circuits at Bell Laboratories. Since receiving the PhD in 1988, he has been on the faculty in Applied Physics at Cornell.