Instruments for Gravitational Wave Astronomy on Ground and in Space.

Gravitatioanl Wave Astronomy progressively becomes this new window on the universe that we expected since tens of years. The technology has now reached a point where large instruments meet a level of sensitivity relevant for astrophysics. Depending on the sector of physics to be addressed, quired. Ground based antennas are already built in Europe, in Japan and in the USA and begin to deliver science data. The ESA/NASA space mission LISA in not yet definitively approved, but a number of teams endeavour to successfully pass the coming project reviews. We review the general principles of the optical detection of gravitation waves. [ABSTRACT FROM AUTHOR]