KEYWORDS: Sensors, Fiber amplifiers, Optical amplifiers, High power fiber amplifiers, Beam splitters, Step index fibers, Standards development, Signal generators, Polarization
Gravitational wave detectors require single-frequency laser sources with challenging requirements regarding beam quality and noise properties. We developed a reliable single-frequency fiber amplifier architecture based on standard step-index large-mode-area fibers and coherently combined two high power beams to enable further power scaling. A combined power of 391 W could be achieved with a combining efficiency of approx. 92 %. The TEM00-mode content of the combined beam was analyzed and a higher-order-mode content of 6.8 % was measured. This yields 365 W linearly polarized output power in the TEM00-mode that is usable for the application.
Gravitational wave detectors require single-frequency laser sources with challenging properties regarding beam quality, polarization, and noise properties. We developed a single-frequency fiber amplifier engineering prototype based on standard step-index polarization maintaining fibers and characterized the 200 W output beam with the complete set of measurements necessary to evaluate the system's performance with respect to the application requirements. The output beam has a TEM00-mode content of 94:8% at 200W and a polarization extinction ratio of 19 dB. In the crucial frequency range from 1 Hz to 100 kHz the frequency noise, relative power noise, and relative pointing noise measurements demonstrated low noise properties. In addition, the pointing noise below 100 Hz is the lowest reported for single-frequency amplifiers with 200W output power. SBS-free operation was demonstrated by monitoring the relative power noise in the MHz frequency range. The system was operated above 200W for 695 h and evaluated again after 650 h of operation. No signs of photodarkening were found.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.