Gold coated optical lens

CSIRO is developing a new generation of advanced optical coatings (dielectric and gold).

High precision optical coatings for international LIGO observatories

CSIRO has manufactured the precision optics (lenses and mirrors) that enable US observatories to detect pulsars, supernovae and black holes by measuring gravitational waves.

  • 24 August 2012

Precision coated optics

From 1995 to 2000 CSIRO High Precision Optics fabricated and certified about 90% of the core optics (mirrors and lenses) for the Laser Interferometer Gravitational-Wave Observatory (LIGO), a joint collaboration managed by MIT and Caltech to detect  and observe cosmic gravitational waves.

These have been installed at the two USA observatories participating in LIGO (Hanford and Livingston).

A super-polished round, flat disc of silica, 24 centimetres in diameter, made for the gravity wave observatory being built by California Institute of  Technology (Caltech) and the Massachusetts Institute of Technology (MIT).

A super-polished, super-flat test mass for the gravity wave observatory being built by Caltech and MIT.

Since 2000 CSIRO has been working with the LIGO consortium to improve the sensitivity of LIGO I detectors.

Currently CSIRO is developing and applying optical coatings for the advanced LIGO recycling cavity optics.  The coatings are a combination of gold coating (for the electrostatic drive and thermal shielding) and dielectric materials for low-loss high-reflectivity, or anti-reflection.

The dielectric coatings are applied with ion beam sputtering technology while the gold coatings are deposited by a magnetron sputtering system.

Why measure gravity waves?

Measuring gravitational wave emissions allows scientists to detect:

  • collisions and coalescences of neutron stars or black holes
  • formation of neutron stars and black holes from supernovae
  • accretion of neutron stars
  • remnants of gravitational radiation created by the birth of the universe.

LIGO employs laser interferometry to detect gravitational waves. The gravitational waves influence the movement of light photons as they bounce up and down between the coated optical mirrors.