High-Power Free-Space Bulk Multiplexer for Satellite Communication Optical Ground Terminal

High throughput optical satellite communication (SATCOM) systems need to rely on effective and robust technology to enable wavelength-division multiplexing (WDM) in a commercially viable way. The main challenge to implement WDM in optical feeder links deals with the multiplexing of high power channels. Currently the levels of power required for...

End-to-End Performance Analysis of Analog Coherent Optical Satellite Feeder Links

Optical feeder links (OFLs) benefit from the vast amount of bandwidth available in the THz-regime of the electro-magnetic spectrum, and could enable future terabit-per-second satellite systems. This study assesses the end-to-end performance of analog coherent OFLs for digital video broadcasting (DVB) applications, employing phase modulation (PM)...

Beam multiplexing for satellite communication optical feeder links

Optical satellite communication is growing fast and among various applications it requires higher throughput optical feeder links. Optical feeder links for satellite communication necessitate very high data throughput, up to 1 Terabit/s and beyond. Amongst several multiplexing strategies, dense wavelength division holds a key position to enable...

GOCAT OGS - DTE

Multiple groups world wide are currently developing laser communication terminals for downlinking data from satellites in the LEO orbit directly to earth in the so call DTE (Direct To Earth) configuration. These terminals will require a network of ground stations to downlink their data. The challenge for the communication industry is the...

TOmCAT OGS – Optical Feederlink

To overcome data rate limitations of RF communication links with satellites, TNO and Airbus Netherlands envision optical free-space communication feeder links for next generation high throughput satellites. This poster presents a feasibility assessment of such links and the technology needed by means of a link budget and a turbulence model of...

On the design of Terabit Class Modems for high-throughput, low-latency and high-availability FSO applications

Conventional modems are designed for Gigabit class connections. To meet the ever-growing demand for higher data rates, this work addresses the challenges and proposes a design for a new generation of Terabit class modems, specifically suitable for free space optics (FSO) communications.

Pre-correction adaptive optics performance for a 10 km laser link

For the next generation of very high throughput communication satellites, free-space optical (FSO) communication between ground stations and geostationary telecommunication satellites is likely to replace conventional RF links. To mitigate atmospheric turbulence, TNO and DLR propose Adaptive Optics (AO) to apply uplink pre-correction. In order...

Key challenges and results in the design of Cubesat Laser Terminals, Optical Heads and Coarse Pointing Assemblies

The anticipated capacity benefit of optical satellite communications has triggered a cascade of technology developments. In this paper, we present three such technologies, namely; i). A cube satellite laser terminal (CubeCAT), ii). A lower Earth orbit satellite optical head (LEOCAT) and iii). A calibration and verification test bench for coarse...

Optical feeder link program and first adaptive optics test results

TNO and DLR envision optical free-space communication between ground stations and geostationary telecommunication satellites to replace the traditional RF links for the next generation of Very High Throughput Satellites. To mitigate atmospheric turbulence, an Adaptive Optics (AO) system will be used. TNO and DLR are developing breadboards to...

Optical technologies for terabit/s-throughput feeder link

To overcome data rate limitations of RF communication links with satellites, TNO and DLR envision optical free-space communication feeder links for next generation high throughput satellites. This paper provides a feasibility assessment of such links and the technology needed. The main results of the link budget and the turbulence modeling of...

TNO optical communications space terminals: Current projects and future plans

This paper presents the activities performed by TNO in the field of Space Laser Communication Terminals for high-volume low cost applications, and its plans for the further development of the required technologies for space terminals with particular emphasis on highly reliable, high performance, cost effective terminals.

Primary mirror control for large segmented telescopes: Combining high performance with robustness

Future large telescopes, such as E-ELT and TMT, will need feedback control of the thousands of actuators underneath their segmented primary mirrors (M1). Differences in actuator dynamics and spatially and temporally changing disturbances make it extremely diffcult to formulate classical controllers which are both suffciently robust and highly...

Control of mirror segment actuators for the European Extremely Large Telescope

Controller design based on dynamic analysis proves compliant performance of highly accurate actuators for piston-tip-tilt correction of primary mirror segments for the European Extremely Large Telescope.

Dynamic analysis and control of mirror segment actuators for the European Extremely Large Telescope

Segmented primary mirror telescopes require dedicated piston-tip-tilt actuators for optimal optical performance. Netherlands Organisation for Applied Scientific Research (TNO) has developed various prototypes of such actuators, in particular for the E-ELT. This paper presents the dynamics analysis and feedback control results for a specific two...

Optimal control of tip-tilt modes on-sky adaptive optics demonstration

An H2-optimal control approach for Adaptive Optics has been validated in an on-sky experiment on a solar telescope. A substantial performance improvement over the integrator control approach is demonstrated for control of the tip-tilt modes. The experimental results correspond reasonably well with simulations based on measured data.

PACT: the actuator to support the primary mirror of the ELT

The European Southern Observatory (ESO) has started technology development for their next generation optical telescope. Due to its ultra large collecting area, The European Extremely Large Telescope (E-ELT) will require a paradigm shift in telescope design to keep the overall program cost at an acceptable level. The E-ELT will feature a 42 meter...