FIRST-PL: Commissioning the first visible photonic lantern spectrograph for sub-diffraction-limit astronomy on Subaru/SCExAO

Sebastien Vievard; Elsa Huby; Sylvestre Lacour; Olivier Guyon; Manon Lallement; Mathias Nowak; Yoo Jung Kim; Aidan Walk; Jehanne Sarrazin; Sergio Leon-Saval; Chris Betters; Julien. Lozi; Miles Lucas; Vincent Deo; Nemanja Jovanovic; Michael Fitzgerald; Barnaby Norris; Thayne Currie; Garima Singh; Sandrine Juillard; Guy Perrin

arXiv · 2608.04372

FIRST-PL: Commissioning the first visible photonic lantern spectrograph for sub-diffraction-limit astronomy on Subaru/SCExAO

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Abstract

FIRST-PL (Fibered Imager foR a Single Telescope - Photonic Lantern) is a newly commissioned visible-light instrument on Subaru/SCExAO achieving spectroscopy below the diffraction limit. The instrument uses a Photonic Lantern (PL)-converting multimode fiber into 19 single-mode outputs-feeding a mid-resolution spectrograph (R 3000, 630-790 nm). On-sky performance demonstrates 40% injection efficiency at 680 nm (Strehl 30%) and 12x throughput improvement over single-mode fibers. Three operational modes enable spectro-astrometry (50 microarcseconds precision demonstrated on beta-CMi), image reconstruction, and high-contrast imaging. FIRST-PL represents a significant advancement in high-throughput photonic instrumentation.

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Sebastien Vievard, Elsa Huby, Sylvestre Lacour, Olivier Guyon, Manon Lallement, Mathias Nowak, Yoo Jung Kim, Aidan Walk, Jehanne Sarrazin, Sergio Leon-Saval, Chris Betters, Julien. Lozi, Miles Lucas, Vincent Deo, Nemanja Jovanovic, Michael Fitzgerald, Barnaby Norris, Thayne Currie, Garima Singh, Sandrine Juillard, Guy Perrin. 2026-08-05. FIRST-PL: Commissioning the first visible photonic lantern spectrograph for sub-diffraction-limit astronomy on Subaru/SCExAO. https://arxiv.org/abs/2608.04372

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