Objective: Implement wavelength division multiplexing (WDM) at 1064 nm wavelength to significantly increase the data rate of the current generation of laser communication terminals
Targeted Improvements: Enable next generation Laser Communication Terminals to provide data rates in excess of 20 Gbps.
Description: The goal of this activity is to demonstrate wavelength division multiplexing (WDM) within the broad amplification window of fibre amplifiers in the 1064 nm wavelength range. This shall enable next generation Laser Communication Terminals to provide data rates in excess of 20 Gbps.
Despite the fact that wavelength division multiplexing (WDM) is mostly associated with operation in the 1550 nm wavelength band, fibre amplifiers operating at 1064 nm are also sufficiently wideband to allow WDM. To implement WDM, the currently used single non-planar ring oscillator laser will need to be replaced with a Bragg grating stabilised single frequency laser diode (laser line-width: 20 mW). The laser diodes shallsupport operation in an optical phased locked loop and shall be tuneable to compensatefor the Doppler shifts encountered using optical inter-satellite links. The laser product family may cover the amplification range of Ytterbium doped amplifiers (e.g. 1064nm - 1083nm).
In addition the WDM system shall be able to utilise incoherent modulation formats such as On/Off-Keying (OOK) or Pulse Position Modulation (PPM) to simplify communication through atmospheric turbulence with an optical ground station. In this way the 3dB advantage of 1064 nm over 1550 nm technology is maintained. The 1064 nm amplifier technology also benefitsfrom increased efficiency and a lower radiation sensitivity when compared to 1550 nm solutions.
The activity shall develop a breadboard demonstrating communication via (as a minimum) 3 wavelengths separated by 0.1 nm (TBC) within the spectral range of a fibre amplifier of >1 Watt power. Thereceiver chain shall provide sufficient attenuation to simulate a LEO-GEO link and shall investigate the channel separation, intermodulation sensitivity and the channelquality with a data rate of (minimum) three times 1 Gbps.
Procurement Policy: C(1) = Activity restricted to non-prime contractors (incl. SMEs). For additional information please go to EMITS news "Industrial Policy measures for non-primes, SMEs and RD entities in ESA programmes".