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...

QKD optical ground terminal developments

Free space optical (FSO) satellite communications has very attractive properties for Quantum Key Distribution(QKD). The quantum channel loss and noise are major factors in setting the maximum achievable secure key rate of QKD systems. Primarily for a LEO satellite node and the BB84 protocol a number of technologies are proposed to reduce 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...

Inline ECE measurements for NTM control on ASDEX Upgrade

The successful use of a tokamak for generating fusion power requires an active control of magnetic instabilities, such as neoclassical tearing modes (NTMs). Commonly, the NTM location is determined using electron cyclotron emission (ECE) and this is used to apply electron cyclotron heating (ECH) on the NTM location. In this paper, an inline ECE...

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...

Advances of TNO's electromagnetic deformable mirror development

TNO is developing Deformable Mirror (DM) technology, targeted for aberration correction in high-end Adaptive Optics (AO) applications in the field of lithography, astronomy, space and laser communication. The heart of this deformable mirror technology is a unique actuator technology based on the variable reluctance principle. The main advantages...

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...

NTM stabilization by alternating O-point EC current drive using a high-power diplexer

At the tokamak ASDEX Upgrade, experiments to stabilize neoclassical tearing modes (NTMs) by electron cyclotron (EC) heating and current drive in the O-points of the magnetic islands were performed. For the rst time, injection into the O-points of the revolving islands was performed via a fast directional switch, which toggled the EC power...

Dimensional stability testing in thermal vacuum of the CHEOPS optical telescope assembly

The CHEOPS mission (CHaracterising ExOPlanet Satellite) is dedicated to searching for exoplanetary transits by performing ultra-high precision photometry on bright stars already known to host planets. A 32cm diameter on-axis Ritchey-Chrétien telescope is used for imaging onto a single cooled detector. With integration times up to 48 hours the...

Systematic characterization of optical beam deflection measurement system for micro and nanomechanical systems

Optical beam deflection (OBD) measurement method is very popular in various types of scanning probe microscopy (SPM) and micro/nanomechanical sensors to measure a mechanical motion. This paper reports the detail design and implementation of a very low drift (2 nm over 1000 s), high bandwidth (40 MHz) and low noise (15 fm/VHz) OBD measurement...

Controlled mirror motion system for resonant diplexers in ECRH applications

High-power resonant diplexers for millimetre waves have various promising applications in ECRH systems. The round-trip resonator length of a diplexer needs to be accurately tuned to match its prescribed functionality. For this purpose one of the mirrors in the FADIS MkIIa diplexer has been mounted on a motion system, in order to control the...