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Proceedings Paper • Open Access

Extremely stable piezo mechanisms for the new gravitational wave observatory
Author(s): Joep Pijnenburg; Niek Rijnveld; Harm Hogenhuis

Paper Abstract

Detection and observation of gravitational waves requires extreme stability in the frequency range 3e-5 Hz to 1 Hz. NGO/LISA will attain this by creating a giant interferometer in space, based on free floating proof masses in three spacecrafts. To operate NGO/LISA, the following piezo mechanisms are developed:

1. A piezo stack mechanism (Point Angle Ahead Mechanism) Due to time delay in the interferometer arms, the beam angle needs to be corrected. A mechanism rotating a mirror with a piezo stack performs this task. The critical requirements are the contribution to the optical path difference (less than 1.4 pm/√Hz) and the angular jitter (less than 8 nrad/√Hz).

2. A piezo sliding mechanism (Fiber Switching Unit Actuator)

To switch from primary to the redundant laser source, a Fiber Switching Unit Actuator (FSUA) is developed. The critical requirements are the coalignment of outgoing beams of <+/-1 micro radian and <+/-1 micro meter. A redundant piezo sliding mechanism rotates a wave plate over 45 degrees.

3. A piezo stepping mechanism (In Field Pointing Mechanism)

Due to seasonal orbit evolution effects, beams have to be corrected over a stroke of +/-2.5 degrees. The critical requirements are the contribution to the optical path difference (less than 3.0 pm/√Hz) and the angular jitter (less than 1 nrad/√Hz). Due to the large stroke, a piezo stepping concept was selected. Dedicated control algorithms have been implemented to achieve these challenging requirements.

This paper gives description of the designs and the ongoing process of qualifying the mechanisms for space applications.

Paper Details

Date Published: 20 November 2017
PDF: 11 pages
Proc. SPIE 10564, International Conference on Space Optics — ICSO 2012, 105640L (20 November 2017); doi: 10.1117/12.2309083
Show Author Affiliations
Joep Pijnenburg, TNO Opto Mechatronics (Netherlands)
Niek Rijnveld, TNO Opto Mechatronics (Netherlands)
Harm Hogenhuis, TNO Opto Mechatronics (Netherlands)


Published in SPIE Proceedings Vol. 10564:
International Conference on Space Optics — ICSO 2012
Bruno Cugny; Errico Armandillo; Nikos Karafolas, Editor(s)

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