The next generation of telecom satellite makes the industry facing a technological rupture to reach high data throughput up to 1 terabit/s, while making communications links reconfigurable during all mission phases. That is why the introduction of optical communication technologies like laser links or photonic payloads in telecom satellites is foreseen to revolutionize the space telecom market. Hence the groundbreaking photonic payload will enable reaching the increasing demand of debit and flexibility thanks to miniaturization. In such photonic payload, the proposed optical switch will provide both the added value of optical fiber and new flexibility, redundancy and adaptability functions. Sodern, a recognized space equipment provider is presently spatializing the DirectLight® 1,55 μm Optical Switching Technology from HUBER+SUHNER Polatis Ltd (UK), the worldwide leader in optical switch technology for ground telecommunications and datacenter networks.
This paper focuses on the development activities of Sodern and Polatis on their Space Optical Switch development both for GEO 1 terabit/s high reliability and for low cost LEO constellations. An overview of the technology evaluations and design studies as well as of breadboard performance and environmental testing will be presented. Finally Sodern will explain the product development roadmap including the upcoming EQM.
A high-precision opto-mechanical breadboard for a lens mount has been assembled by means of a laserbased
soldering process called Solderjet Bumping; which thanks to its localized and minimized input
of thermal energy, is well suited for the joining of optical components made of fragile and brittle
materials such as glasses. An optical element made of a silica lens and a titanium barrel has been studied
to replicate the lens mounts of the afocal beam expander used in the LIDAR instrument (ATLID) of the
ESA EarthCare Mission, whose aim is to monitor molecular and particle-based back-scattering in order
to analyze atmosphere composition. Finally, a beam expander optical element breadboard with a silica
lens and a titanium barrel was assembled using the Solderjet Bumping technology with
Sn96.5Ag3Cu0.5 SAC305 alloy resulting in a low residual stress (<1 MPa) on the joining areas, a low
light-depolarization (<0.2 %) and low distortion (wave-front error measurement < 5 nm rms) on the
assemblies. The devices also successfully passed humidity, thermal-vacuum, vibration, and shock tests
with conditions similar to the ones expected for the ESA EarthCare mission and without altering their
Soldering using metallic solder alloys is an alternative to adhesive bonding. Laser-based soldering processes are especially well suited for the joining of optical components made of fragile and brittle materials such as glass, ceramics, and optical crystals. This is due to a localized and minimized input of thermal energy. Solderjet bumping technology has been used to assemble a lens mount breadboard using specifications and requirements found for the optical beam expander for the European Space Agency EarthCare Mission. The silica lens and a titanium barrel have been designed and assembled with this technology in order to withstand the stringent mission demands of handling high mechanical and thermal loads without losing the optical performance. Finally, a high-precision optomechanical lens mount has been assembled with minimal localized stress (<1 MPa) showing outstanding performance in terms of wave-front error and beam depolarization ratio before and after environmental tests.
Solder joining using metallic solder alloys is an alternative to adhesive bonding. Laser-based soldering processes are especially well suited for the joining of optical components made of fragile and brittle materials such as glasses, ceramics and optical crystals. This is due to a localized and minimized input of thermal energy. Solderjet bumping technology has been used to assemble a lens mount breadboard taking as input specifications the requirements found for the optical beam expander for the European Space Agency (ESA) EarthCare Mission. The silica lens and a titanium barrel have been designed and assembled with this technology in order to withstand the stringent mission demands; handling high mechanical and thermal loads without losing its optical performances. Finally a high-precision opto-mechanical lens mount has been assembled with a minimal localized stress (<1 MPa) showing outstanding performances in terms of wave-front error measurements and beam depolarization ratio before and after environmental tests.
We demonstrate experimentally that plasmonic nanoantennas made of metal-insulator-metal ribbons can be used to tailor the spectral emissivity of a gold surface in the infrared. Two areas of a gold mirror sample were covered with various combinations of nanoantennas. Their emissivity was characterized thanks to a dedicated bench, based on the combination of a Fourier transform spectrometer and a microbolometer infrared camera. A near unity polarized emission on two distinct infrared bands is obtained on the respective two areas, which is coherent with theoretical predictions.
We show both theoretically and experimentally that metal-insulator-metal resonators can be combined within the same subwavelength period and still behave independently. This permits to conceive surface with customizable absorption, which can for instance be used in dual band absorber or in omnidirectional wideband absorber. An energetic analysis can also be applied on these more complex antennas geometries, which highlights a sorting effect: at each resonance wavelength, the photons are funneled towards the apertures of the corresponding MIM cavity.
We investigate in this paper the potential of carbon nanotubes for infrared bolometers. A method to obtain
CNT film layer and technological processes to obtain matrix of devices are presented. The electrical
characterization of samples establishes the quality of our technology i.e. low contact resistance, and weak
dispersion between devices. The potential of carbon nanotubes films as bolometric material is investigated by
measuring the thermal dependence of their resistance and by comparison with amorphous silicon (one of the
leading material for bolometric applications). Optical measurements of CNT films in the infrared and THz
ranges show a relatively high absorption for a few hundreds nanometers thick material. Eventually the
infrared (8-12 μm) photo-response of a first demonstrator is presented and discussed.