Compact packaging of pulsed 1-micron and 1.55-micron fiber amplifiers (Conference Presentation)

We have developed a packaged fiber amplifier configuration that allows for nearly two orders of magnitude of pulse width adjustment from 1ns to >800ns. This has been developed for both the 1-micron and 1.55-micron spectral regions. Our 1.55-micron fiber laser is packaged into a 6.63 x 8.65 x 3.47 in3 box, while our 1-micron fiber laser is packaged into a 13.68 x 8.68 x 3.56 in3 box, with the larger package a result of larger fiber components. These lasers offer a wide range of adjustable operating points, with total output ultimately limited by available pump power. For 1ns pulses, our 1.55-micron system generates up to 6μJ of pulse energy (>6kW peak) with transform-limited spectral output. Higher energies and output powers are achievable (up to 33μJ at 25kW peak), but the spectral output broadens slightly due to nonlinearities with <5ns pulse durations. For 1ns pulses at 1-micron, the system can generate 10uJ pulse energy (>10kW peak) with high spectral purity. At >10ns pulse durations, the same laser can generate up to 40μJ pulse energy (pump limited). A unique aspect of our design is that a single fiber laser package can be electrically adjusted to produce the full range of pulse widths at repetition rates ranging from 100kHz to <1MHz with well-behaved output pulse shapes and no rising-edge pulse distortions typically seen in high gain amplifiers. In this paper, we discuss our laser architecture, performance, packaging layout, packaging limitations, and a path toward more compact designs using standard fiber components.