As part of the Lisa Technology Package (LTP) on board the LISA-PATHFINDER spacecraft, the LISAPATHFINDER interferometer is of the heterodyne Mach-Zehnder type. It requires as input two light beams derived from the same source but with a small frequency difference (a few kHz). These two optical beams are produced in the Laser Assembly (LA) via the "Laser Modulation Unit" (LMU). The LMU includes an optical bench, two Acousto-Optic Modulators and two Optical Delay Lines .
His fifteen years of research in electronics have enabled Frank Claeyssen to take his piezoelectric actuators to a promising industrial stage.
Piezomotors are well known in various applications where high precision actuation is required like AFM or handling equipment for semiconductor production. Their specific low speed in direct drive and high torque characteristics combined with high holding torque in off power conditions make them very attractive for any positioning application and especially space mechanisms where low electrical consumption is always sought. A new concept of rotating stepping piezomotor has been developed in the frame of the LISA space project where the mechanism of the telescope orientation was addressed.
A moving coil actuator for high precision positioning and compatible with space technology specifications has been designed and successfully tested. General space technology requirements are the use of no degassing material, no lubrication, low mechanic time constant, low electrical power consumption, and thermal energy evacuation through radiating and conducting exchanges (no convection because of operation in vacuum environment). These specifications have been accounted in the design, the realisation and the test of a successful prototype: Thanks to a good design of thermal drains, the actuator presents a high force versus weight ratio.
Piezoelectric actuators find their first applications in active space optics. The purpose of this paper is to describe the state of the art and some applications. Piezo actuators display attractive features for space applications, such as precise positioning, unlubricated, non magnetic and compact features, and low power consumption. However, piezo mechanisms cannot be considered separately from their driving and control electronic.
The DTT35XS is a new piezo mechanism coming from CEDRAT TECHNOLOGIES lab in February 2002. It comes from a development for space needs defi ned with the CNES (the French space agency), and for which a first application was found in the frame of “PHARAO”. This mechanism is based on two pairs of APA35XS, Amplifi ed Piezo Actuators displaying 35 µm of stroke each, arranged in cross configuration. The mechanism allows both a defl ection of +/- 2 mrad around the X and Y axis and a vertical displacement of 35 µm in the Z direction.
The XY25XS stage is an original micro positioning mechanism developed, built and marketed by CEDRAT TECHNOLOGIES. This mechanism relieds on the Amplified Piezo Actuators (APA) technology patented by CTEC