OSTIblog Articles in the Laser Interferometer Gravitational-Wave Observatory (LIGO) Topic

Incredible Laser Interferometers

  Laser Interferometer Gravitational-Wave
  Observatory (LIGO) in Livingston, LA.  
  Image credit: LIGO Laboratory

Interferometers are investigative tools used in many fields in science and engineering.  They work by merging two or more sources of light or other waves to create an interference pattern, which can be precisely measured and analyzed.  Interferometers are making possible significant advances in scientific research.  One of these advances is in astronomy, where laser interferometers are opening a new era in the exploration of the universe.

In 1972, a young Massachusetts Institute of Technology physics professor, Rainer Weiss, drew up a teaching exercise using a basic concept for an interferometer to detect gravitational waves.  This work later became the blueprint for the Laser Interferometer Gravitational-Wave Observatory (LIGO), a national facility for gravitational wave research.  LIGO is funded by the National Science Foundation and other public and private institutions.

LIGO currently consists of two of the world’s largest and most sensitive interferometers located 1,865 miles apart on DOE’s Hanford Site at Hanford, Washington, and in Livingston, Louisiana, shown in the image above.  These incredible laser interferometers operate in unison using laser interferometry to measure the minute ripples in space-time caused by passing gravitational waves from space events.  Observed signals from the Hanford and Livingston detectors are then superimposed to verify the gravitational waves and their origin.

LIGO’s search for gravitational waves began in 2002 but no waves were discovered.  LIGO was then...

Related Topics: Laser Interferometer Gravitational-Wave Observatory (LIGO)