Description

Objective: The objective of the activity is to develop a size optimised telescope for optical communication terminals with optically separated transmit and receive path. Targeted Improvements:100% improvement (doubling) of user terminal accessibility (no need for A and B terminals), reuse of bandwidth allocation and implementation simplicity of terrestrial coherent >100 Gbps transceivers (no polarisation not wavelength issues). Description: This activity will develop an optical telescope for space, optimised for asymmetrical optical links such as in direct to Earth (DTE) communications. The asymmetry is in a much larger ground telescope diameter(compared to the space telescope), where the reduction in optical link budget (from separated Tx and Rx apertures in space) does not pose an unacceptable penalty. The space telescope design may be such that the central obscuration by the secondary mirror is used to launch the transmit beam. There the obscuration ratio will be link budget optimised while taking advantage of a reduced pointing accuracy requirement from an increased transmit beam divergence. The space telescope design may also have two laterally separated Tx/Rx apertures and a trade-off between lateral and coaxial separation will be performed based on minimising the required volume for a particular aperture diameter. A Tx/Rx beam alignment capability will be implemented into the telescope design.