The development of a cryogenic optical delay line for DARWIN

Abstract

The assembly and integration of the breadboard cryogenic optical delay line has been completed. The measured optical path difference stability is 1.3 nm rms on a test bench with 23 /spl mu/m rms vibration level (the test bench has a much higher disturbance spectrum than the DARWIN spacecraft). A full verification test program is currently being carried out by Alcatel Space and SAGEIS-CSO, including thermal vacuum testing at 40 K.