ARTES 4.0

ARTES (Advanced Research in Telecommunications Systems) is an ESA program to further develop new technologies and methods for satellite communications.

Details about this program can be found here: ARTES 4.0

Satellites currently communicate primarily with each other and with their respective ground stations via radio. This uses high-frequency radio waves in the GHz range. However, the available data rates are increasingly reaching their limits. Therefore, research is being conducted worldwide to find ways to replace current radio-based communication with optical methods.

Satellite communication, which uses so-called laser terminals instead of radio wave transmitters and receivers, achieves a data rate between 10 and 100 times higher than before.

A further advantage of optical communication is that, compared to communication via radio waves, it is highly directional and therefore cannot be intercepted undetected.

At the heart of laser terminals is an optical system in which laser beams are transmitted and received via highly reflective mirrors. In optical communication between satellites, the laser light propagates through the vacuum without deflection or scattering. However, during optical communication between satellites and their ground stations, the laser beams can be affected by scattering in the Earth’s atmosphere or even by obscuration by clouds.

To solve this problem, the ARTES 4.0 SPL optical communication program develops a compact and low profile optical head for airborne optical communication terminals

For one of these terminals, we coated some mirrors with a highly reflective silver coating: The reflectivity of this layer in the optical range is R>90% at 400 nm and R>98% above a wavelength of 800 nm. These high reflectivities guarantee the lowest possible losses during operation of the laser terminal.