A remotely-pumped 130-W 1178-nm single-frequency linearly-polarized Raman fiber amplifier

Remotely pumped by a single-mode, polarization-maintaining (PM) 1120-nm fiber laser, a single-frequency linearly-polarized 1178-nm Raman fiber amplifier (RFA) has been developed with a maximum continuous-wave (CW) output power of 130-W. This remotely-pumped high-power RFA system features the same modular, compact and ruggedized design as the proven SodiumStar 20/2 and provides the potential for a guide star laser with a 589-nm output power approaching 100-W, assuming a 10 to15% D2b sideband content and a typical overall conversion efficiency of a resonant second harmonic generator of ~ 70%. Utilizing innovative patented remote pump delivery technology, the 589-nm laser head (LH), which includes the RFA itself, can now be separated physically from the electronics cabinet (EC), which hosts the bulky and heat-generating control electronics, the 1178-nm seed laser, the fiber laser power supply and the fiber laser pump module. The physical separation distance from the LH to the EC can now be as long as 30-m for a 130-W RFA and up to 50-m for a 100-W RFA. The remote pumping capability of this high-power RFA offers important system configuration flexibility and is well-suited for laser guide star assisted adaptive optics systems in ground-based large-aperture astronomical telescopes, optical ground stations and space debris tracking systems, particularly when the available laser launching platform space is strictly limited.