Prototype of an ultra-stable optical cavity for space applications.

We report the main features and performances of a prototype of an ultra-stable cavity designed and realized by industry for space applications with the aim of space missions. The cavity is a 100 mm long cylinder rigidly held at its midplane by a engineered mechanical interface providing an efficient decoupling from thermal and vibration perturbations. Intensive finite element modeling was performed in order to optimize thermal and vibration sensitivities while getting a high fundamental resonance frequency. The system was designed to be transportable, acceleration tolerant (up to several g) and temperature range compliant [-33 degrees C; 73 degrees C]. Thermal isolation is ensured by gold coated Aluminum shields inside a stainless steel enclosure for vacuum. The axial vibration sensitivity was evaluated at (4 +/- 0.5) x 10(-11)/(m.s(-2)), while the transverse one is < 1 x 10(-11)/(m.s(-2)). The fractional frequency instability is less than or similar to 1 x 10(-15) from 0.1 to a few seconds and reaches 5-6 x 10(-16) at 1s. (C) 2012 Optical Society of America