Photonic Integrated Circuits for the Habitable Worlds Observatory: Science Drivers, Material Platforms, Arrayed-Waveguide Spectrographs, and a Space-Qualification Roadmap

This arXiv paper examines how astrophotonics can serve NASA's Habitable Worlds Observatory (HWO), whose ultraviolet, optical, and near-infrared instruments must be simultaneously compact, mechanically and thermally stable, high-throughput, and replicable at large channel counts.

It argues that space-qualified photonic integrated circuits (PICs) and optical fibres are key platforms for these requirements because they manipulate light at the diffraction limit within micron-scale single-mode waveguide circuits. An astrophotonic instrument can fully guide starlight from the focal plane to the detector, eliminating scatter and ghosts and offering excellent stability with no moving parts.

The paper is organized around four topics: (I) the HWO observing modes best implemented with photonic instruments; (II) the waveguide and fibre materials that can span HWO's demanding 100 nm–2.5 μm wavelength range; (III) the potential of arrayed-waveguide-grating (AWG) spectrographs to reach the resolving powers and throughputs HWO science requires; and (IV) the steps needed to space-qualify PICs and fibres against radiation, thermal cycling, vacuum, and launch loads. For each topic, it extracts concrete technical requirements and assesses the current Technology Readiness Level (TRL).

Its main contribution is to unify HWO science drivers, candidate-aperture photon budgets, UV-to-near-infrared material platforms, AWG architectures, and space-qualification requirements within a single photon-budget framework. That framework pairs each claimed benefit with a measurable requirement, a TRL, and an environmental test that can retire the associated risk. It also presents a phased roadmap to advance critical photonic components from their present TRL ~2–5, depending on platform and application, to the TRL ~6 needed at HWO's instrument-definition gate.