Photonic lantern — astrophotonic mode-conversion device that couples a multimode telescope feed (or a small few-mode fiber) into a bundle of single-mode fibers, while preserving optical throughput.
Why it matters for exoplanet science
Conventional spectrographs lose efficiency when feeding multimode light; single-mode spectrographs offer extreme spectral stability but cannot accept multimode focal-plane light directly. Photonic lanterns bridge this gap, enabling:
- Compact single-mode integrated-photonic spectrographs at telescope focal planes.
- Coupling of coronagraph “dark-hole” light into single-mode fibers for high-contrast exoplanet spectroscopy.
Vault use
- PEEPSS — enabling technology for the proposed HWO photonic-lantern-fed spectrograph + focal-plane wavefront sensor (src-peepss-hwo-spectrograph-2026-04).