Can Holograms replace optics in space?

Inter satellite laser communication is vital for the high data rates required for current and future space applications, such as satellite constellations.

Currently, laser communication devices are rather expansive, have long manufacturing times.

For ground-based operations, to reduce costs and utilise mass manufacturing techniques, optical lithography is used.

A new activity with GSTP and Tesat-Spacecom, Germany, has simulated whether a computer-generated hologram could be used as a replacement for these refractive/ reflective optics.

Three different optimisation algorithms were used to find the best performing hologram structure, although all solutions suffered from higher-order diffraction issues.

Overall, the hologram had around six percent lower power throughput to instruments, such as a photodetector. All other properties, especially imaging properties on the photodetector, thermal stability, and stray light generation met current specifications.

While, based on the assessment, a hologram cannot currently be used as a universal replacement for reflective/refractive optics, the lower cost, reduction in components and decreased mass could compensate for the decrease in efficiency when used, as intended, in large constellations.

Next, the activity will manufacture the holograms to test and compare them to these simulations.

4000131100 closed in May 2021.