Speaker
Description
Proposed future gravitational wave detectors place high demands on their stabilized laser system. Especially the proposed interferometers operating with cryogenically cooled silicon mirrors demand another laser wavelength than current detectors. In addition, some of these detectors are expected to be sensitive to gravitational waves down to a few hertz.
We present a prototype for a pre-stabilized laser system at 1550 nm wavelength with frequency and power stabilizations optimized for the needs of gravitational wave detectors. A power stabilization with shot noise limited performance below a relative power noise of $1\times10^{-8}\textrm{Hz}^{-1/2}$ between 100 Hz to 100 kHz and an active frequency stabilization with a unity-gain frequency above 2 MHz were operated simultaneously. Out-of-loop measurements are performed to characterize the achieved stability and to analyze sensor noise limits.
Further research and development are needed to extend this demonstrated high stability towards the low-frequency band of the Einstein Telescope low-frequency interferometers. We present a specific experiment designed to analyze the fundamental sensing and control limitations at these low frequencies in our laser system.
