Institute of Transport and Automation Technology Research Publications
High power, single-frequency, monolithic fiberamplifier for the next generation of gravitationalwave detectors

High power, single-frequency, monolithic fiberamplifier for the next generation of gravitationalwave detectors

Categories Zeitschriften/Aufsätze (reviewed)
Year 2019
Authors Wellmann, F.; Steinke, M.; Meylahn, F.; Bode, N.; Willke, B.; Overmeyer, L.; Neumann, J.; Kracht, D.
Published in Opt. Express 27, 28523-28533
Description

Low noise, high power single-frequency lasers and amplifiers are key components of interferometric gravitational wave detectors. One way to increase the detector sensitivity is to increase the power injected into the interferometers. We developed a fiber amplifier engineering prototype with a pump power limited output power of 200 W at 1064 nm. No signs of stimulated Brillouin scattering are observed at 200 W. At the maximum output power the polarization extinction ratio is above 19 dB and the fractional power in the fundamental transverse mode (TEM00) was measured to be 94.8 %. In addition, measurements of the frequency noise, relative power noise, and relative pointing noise were performed and demonstrate excellent low noise properties over the entire output power slope. In the context of single-frequency fiber amplifiers, the measured relative pointing noise below 100 Hz and the higher order mode content is, to the best of our knowledge, at 200 W the lowest ever measured. A long-term test of more than 695 h demonstrated stable operation without beam quality degradation. It is also the longest single-frequency fiber amplifier operation at 200 W ever reported. [656]

DOI 10.1364/OE.27.028523