Laser displacement sensor with application to gravitational radiation detection.
The principles of operation of a novel laser displacement sensor are described. The intended application of the sensor is to measure displacements induced by gravitational radiation. The laser sensor is composed of three coupled cavities, defined by two laser mirrors and the mirrors of a Fabry-Perot etalon placed inside the laser cavity. The laser is forced to oscillate in two longitudinal modes by a Fox-Smith internal mode selector. It is shown that the laser system can be made to operate in a condition where the beat frequency between these modes has an enhanced sensitivity to relative displacements between the etalon mirrors. A He-Ne laser displacement sensor was constructed, and a displacement sensitivity of 4.6 x 10(12) Hz/cm was obtained. This value is shown to be in good agreement with the value predicted by a theoretical analysis of the sensor performance.
M
M
Weksler
Z
Z
Vager
G
G
Neumann