Radiall (France)

About: Radiall (France) is a company organization based out in Aubervilliers, France. It is known for research contribution in the topics: Multi-mode optical fiber & Fiber optic splitter. The organization has 19 authors who have published 4 publications receiving 10 citations.

High-throughput optical inter-board interconnects for next-generation on-board digital transparent processors

Abstract: The satellite telecommunication sector is continuously facing new challenges. Operators turn towards increasing capacity payloads with higher number of beams and broader bandwidth, in order to cope with exhausting orbital positions and to lower the cost of in-orbit delivery of bit. Only satellites able to provide high data rate connections to numerous users are expected to achieve affordable communication prices. On the other hand, as the telecom market grows and the range of offered services (HDTV, Video On Demand, Triple Play), operators call for more versatile solutions to quickly grasp new markets and to adapt to these evolutions over the average 15 years of a satellite lifetime. Flexible payloads have found an increasing interest for a number of years. Flexibility is considered as a means for a better commercial exploitation of a satellite fleet and a better allocation of resource in response to traffic evolution and/or changing business plans, with potential advantages such as a wider range of applications, less customization for specific missions, increased production runs of equipment, enhancement of reliability, reduction of equipment cost, reduction of program schedules [1]. Flexibility is expected to be offered in spectrum management and frequency plan, in coverage, or in the repeater power allocation. The industry is taking up the challenge both by improving current telecom satellites and offering new payload technology, more flexible and able to address the new markets. From a system integrator perspective, flexibility is as an opportunity to design more generic payloads, that can be customized during or after fabrication only, thus shortening the design-to-manufacturing cycle, and improving the industry competitiveness.

Absolute distance measurements by laser interferometry

Abstract: 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.

Free Space Optical Interconnect (FSOI) modules for short range data transfer applied to board to board high rate communication

Abstract: 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.

Reliability of fiber arrays

Abstract: The packaging of optical components (splitters, WDM, VOA, switches) used in telecommunication applications uses very often Fiber Arrays: it is indeed a very practical component to connect high channel count components (from 1 to 48 channels typically) to the outside world. These Fiber Arrays can be in different formats: standard, focusing, collimating, with single mode fiber or polarization maintaining fiber. But the optical performance of the packaged component is primarily linked to the performance of the Fiber Array. Also, the reliability of the packaged component is mainly determined by the reliability of the Fiber Array, and the way it is attached to the component. The optical performance includes mainly the fiber position error (Core Offset), which determines the insertion loss, but also the polishing induced parameters: polishing angles, surface planarity, fiber protrusion. Optical parameters are also important: excess loss, PDL, and return loss. During the presentation will be related some measurement options, and some results. The reliability of the fiber array is also very important, in order to meet the Telcordia qualification on the packaged product. Unfortunately, these standards, which apply to the packaged component, does not describe qualification procedures for Fiber Arrays, leaving some uncertainty on how to assess the reliability of the product. Different qualification options will be discussed, and some Telcordia qualification results shown.