Thus, for the needs of PEGASE mission – a possible DARWIN in flight demonstration- SAGEIS-CSO has been asked by CNES to design a fine longitudinal sensor able to work at 120 K while performing displacement measurements at a working distance range of 25 to 250 m. Its required performances are a resolution and a precision of 25 nm. This activity succeeds to the MOUSE II system development, which has demonstrated the ability to obtain the required laser metrology using a frequency stabilised laser, a compact and totally passive Michelson type sensor head plus a detection unit for data processing. Optical signals are routed using fibres, allowing the sensor head to be alone in a cryogenic environment. Now, the goal is to obtain a validated prototype at a MQ level by the end of 2007. For that, the laser source will be an update of the flight models made for IASI, using a more powerful DFB diode, pin-to-pin compatible with the previous design, and then giving minor changes. The current regulation was optimized in order not to degrade the narrow diode spectral width. The opto-thermo-mechanical design of the sensor head, in collaboration with AAS, is also under progress, and constitutes the major evolution of the MOUSE II. |
Laser sources
Sensors
Visibility
Head
Diodes
Semiconductor lasers
Cryogenics