Abstract
On September 14, 2015, the two detectors of the Laser Interferometer Gravitational-Wave Observatory
(LIGO) simultaneously received a characteristic transient waveform. After detailed analysis and careful
validation of the signal, it was determined that the signal came from the inspiral and merger of two black
holes in a binary system 1.3 billion light years from earth. This was the first direct detection of GWs and
the first observation of a binary black hole merger.1) LIGO detected two more binary black hole mergers
in 2015 and 2017.2,3) In this article, GW detection using high precision laser interferometry is reviewed.
Technological approaches in the current LIGO detectors will be introduced, as well as challenges for
future generation detectors.
