I am delighted to present this focus issue which brings together articles on the new generation of gravitational wave detectors.
The quest to detect gravitational waves directly has accelerated in the past decade with the successful operation of a first generation of large interferometric detectors. The lessons learned from the first-generation detectors fed into the design of advanced detectors which are now being constructed and commissioned and will soon begin collecting data. Higher laser power, sophisticated mirror suspensions and numerous other improvements will extend the distance reach of the detectors by an order of magnitude and finally record the tiny gravitational-wave signals traversing Earth. This focus issue examines the advanced techniques and detectors currently being assembled, tested and prepared.
Currently, the focus issue features articles from the GEO600 and KAGRA collaborations. Articles from the Advanced Virgo and Advanced LIGO collaborations will be added to the issue soon.
I hope you enjoy reading about the latest developments on these experiments.
Classical and Quantum Gravity