A double-channel Michelson type interferometer is presented which allows absolute distance measurement up to 3 m with an uncertainty of 0.1 um. It used the principle of synthetic wavelength and can be used under vacuum or in any gaseous medium with the help of a new type of source called an air-wavelength standard. The CNES is interested in an absolute measurement both in space vacuum and on the ground, in air to characterize optical instruments.
In the framework of the preparation of the Darwin mission, Alcatel Space has been developing a Multi- Aperture Imaging Interferometer (MAI²) for ESA. The main purpose of this activity is to achieve a deep extinction rate, or "nulling", in the laboratory. The performance goal is a 106 nulling of a simulated star. A second objective is to image a planet-like source. The selected operating wavelength is centred around 1.55 microns, with a relative bandwidth of a few percent. The selected function conceptual designs can be updated to the Darwin spectral range (6-18μm).
In the frame of the CNES R and T activity related to laser metrology, SAGEIS-CSO is actually developing a new smart interferometric sensor, last to arrive in the “MOUSE” family. In this article, we give at first a brief oversight of the MOUSE interferometric concept as well as its performances for two kinds of applications. Secondly, some interesting other set-ups for space applications are mentioned and finally we present modifications that the system will undergo in order to be compliant with long distance measurements. These different developments point out the ability of the MOUSE/IASI interferometric system to be a powerful metrological instrument for space environment.
To provide more flexibility in inter-board communication in blade chassis, we developed a Free Space Optical Interconnect (FSOI) system for short range high speed data transfer. We designed robust and low footprint components compliant with both a use in milaero environment and an operation up to 5 and 10 Gbps. The 5Gpbs configuration demonstrated large tolerance to misalignment between emitter and receiver modules: +1.5/-1 mm along optical axis, lateral tolerance of +/-1 mm and angular tolerances of +/-1.5°. Reliable performances have been demonstrated over a temperature range from -30°C to 80°C and constraint environment as thermal and damp heat cycles and vibrations. Increase the data rate of the FSO device one step beyond up to 10 Gbps requires dealing with mode partitioning troubles generated by the use of VCSEL lasers. We designed and evaluated an improved opto-mechanical combination to overcome this drawback. The resulting device shows error free 10 Gbps data transfer while keeping large tolerance to Tx/Rx misalignments.
The Multi-Aperture Imaging Interferometer (MAI2), which Alcatel Space has been developing for ESA for deep nulling demonstration in preparation of the Darwin project, is based on an innovative layout, where both beam combination and modal wave-front filtering functions are achieved by means of an Integrated Optics (IO) component. Two different components, based on different designs and technologies, have been developed and characterised by LAOG with detailed design and manufacturing performed by IMEP/GeeO/LETI. SAGEIS-CSO (optical path control) and Alcatel Space have developed the other breadboard functions. The MAI² interferometer achieved stable Darwin-class nulling (10-5) of a simulated star in monochromatic light, and with a relative bandwidth of several percent (10-4). Operation in non-polarised light, with unchanged nulling performances, was also demonstrated. Preliminary characterisation of the relationship between nulling and bandwidth is also provided.
In the frame of the CNES R&T activity related to laser metrology, SAGEIS-CSO is actually developing a new smart interferometric sensor, last to arrive in the "MOUSE" family. In this article, we give at first a brief oversight of the MOUSE interferometric concept as well as its performances for two kinds of applications. Secondly, some interesting other set-ups for space applications are mentioned and finally we present modifications that the system will undergo in order to be compliant with long distance measurements. These different developments point out the ability of the MOUSE/IASI interferometric system to be a powerful metrological instrument for space environment.
12 IASI is a key instrument of the payload on METOP, a European meteorological platform. METOP will provide meteorology with atmosphere emission spectra, allowing to set atmosphere temperature and moisture profiles with high accuracy. In order to achieve these specifications, several new and innovative technologies and technical answers have had to be developed. Among them, the reference laser of IASI presents challenging concepts and widely uses the last commercial developments of telecommunication technologies. The reference laser is frequency locked onto a molecular reference absorption line providing a very stable frequency behavior over the several year duration of the instrument life. The principle is well known for atomic clocks and has been adapted to the commercial availability of reliable telecommunication lasers. Semiconductor laser modules, optical fibers and fibered components are used to achieve a compact and reliable subsystem. The availability of such space compliant frequency stabilized laser sources opens new opportunities in the field of optical metrology such as interferometry and multi- aperture telescope co-phasing.