Spectroscopy using a visible photonic lantern at the Subaru telescope: Laboratory characterization and first on-sky demonstration on Ikiiki (α Leo) and `Aua (α Ori)
arXiv:2409.06958 · doi:10.1051/0004-6361/202450234
Abstract
Photonic lanterns are waveguide devices enabling high throughput single mode spectroscopy and high angular resolution. We aim to present the first on-sky demonstration of a photonic lantern (PL) operating in visible light, to measure its throughput and assess its potential for high-resolution spectroscopy of compact objects. We used the SCExAO instrument (a double stage extreme AO system installed at the Subaru telescope) and FIRST mid-resolution spectrograph (R 3000) to test the visible capabilities of the PL on internal source and on-sky observations. The best averaged coupling efficiency over the PL field of view was measured at 51% +/- 10% with a peak at 80%. We also investigate the relationship between coupling efficiency and the Strehl ratio for a PL, comparing them with those of a single-mode fiber (SMF). Findings show that in the AO regime, a PL offers better coupling efficiency performance than a SMF, especially in the presence of low spatial frequency aberrations. We observed Ikiiki (alpha Leo - mR = 1.37) and `Aua (alpha Ori - mR = -1.17) at a frame rate of 200 Hz. Under median seeing conditions (about 1 arcsec measured in H band) and large tip/tilt residuals (over 20 mas), we estimated an average light coupling efficiency of 14.5% +/- 7.4%, with a maximum of 42.8% at 680 nm. We were able to reconstruct both star's spectra, containing various absorption lines. The successful demonstration of this device opens new possibilities in terms of high throughput single-mode fiber-fed spectroscopy in the Visible. The demonstrated on-sky coupling efficiency performance would not have been achievable with a single SMF injection setup under similar conditions, partly because the residual tip/tilt alone exceeded the field of view of a visible SMF (18 mas at 700 nm). Thus emphasizing the enhanced resilience of PL technology to such atmospheric disturbances. The additional
Accepted in Astronomy and Astrophysics journal on 9/11/2024
References in corpus (16)
- Two accreting protoplanets around the young star PDS 70
- The Photonic Lantern
- Hints for a Turnover at the Snow Line in the Giant Planet Occurrence Rate
- Combining high-dispersion spectroscopy (HDS) with high contrast imaging (HCI): Probing rocky planets around our nearest neighbors
- Images of Embedded Jovian Planet Formation At A Wide Separation Around AB Aurigae
- Efficient injection from large telescopes into single-mode fibres: Enabling the era of ultra-precision astronomy
- Direct Imaging and Astrometric Detection of a Gas Giant Planet Orbiting an Accelerating Star
- The X-Shooter Spectral Library (XSL): Data Release 2
- The Effects of Stellar Population and Gas Covering Fraction on the Emergent Lyman Alpha Emission of High-Redshift Galaxies
- Direct Imaging Discovery and Dynamical Mass of a Substellar Companion Orbiting an Accelerating Hyades Sun-like Star with SCExAO/CHARIS
- First starlight spectrum captured using an integrated photonic micro-spectrograph
- Efficient detection and characterization of exoplanets within the diffraction limit: nulling with a mode-selective photonic lantern
- Direct-imaging Discovery of a Substellar Companion Orbiting the Accelerating Variable Star, HIP 39017
- Visible and Near Infrared Laboratory Demonstration of a Simplified Pyramid Wavefront Sensor
- Design considerations of photonic lanterns for diffraction-limited spectrometry
- Single-aperture spectro-interferometry in the visible at the Subaru telescope with FIRST: First on-sky demonstration on Keho'oea (α Lyrae) and Hokulei (α Aurigae)