@inproceedings{5e173463f3f94e5baea8a01fb766b047,
title = "Modal noise mitigation in a photonic lantern fed near-IR spectrograph",
abstract = "Recently we have demonstrated the potential of a hybrid astrophotonic device, consisting of a multi-core fiber photonic lantern and a 3D waveguide reformatting component, to efficiently reformat the multimode point spread function of a telescope to a diffracted limited pseudo-slit. Here, we report on an investigation into the potential of this device to mitigate modal noise-one of the main hurdles of multi-mode fiber-fed spectrographs. The modal noise performance of the photonic reformatter and other fiber feeds was assessed using a bench-Top spectrograph based on an echelle grating. In a first method of modal noise quantification, we used broadband light as the input, and assessed the modal noise performance based on the variations in the normalized spectrum as the input coupling to the fiber feed is varied. In a second method, we passed the broadband light through an etalon to generate a source with spectrally narrow peaks. We then used the spectral stability of these peaks as the input coupling to the fiber feed was varied as a proxy for the modal noise. Using both of these approaches we found that the photonic reformatter could significantly reduce modal noise compared to the multi-mode fiber feed, demonstrating the potential of photonic reformatters to mitigate modal noise for applications such as near-IR radial velocity measurements of M-dwarf stars. ",
keywords = "astrophotonics, exoplanet detection, modal noise, photonic lanterns, radial velocity, spectrographs, ultrafast laser inscription, waveguides",
author = "Pike, {Fraser A.} and Aur{\'e}lien Benoit and MacLachlan, {David G.} and Harris, {Robert J.} and Itandehui Gris-S{\'a}nchez and David Lee and Birks, {Timothy A.} and Thomson, {Robert R.}",
note = "Funding Information: This work was funded by the UK Science and Technology Facilities Council (STFC) – STFC grant no. ST/N000625/1, and by the European Union{\textquoteright}s Horizon 2020 research and innovation program under grant no. 730890 (OPTICON – Optical Infrared Coordination Network for Astronomy). FAP acknowledges support via an Engineering and Physical Sciences Research Council (EPSRC) iCASE studentship part funded by Renishaw. Publisher Copyright: {\textcopyright} 2020 SPIE. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.; Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation IV 2020 ; Conference date: 14-12-2020 Through 22-12-2020",
year = "2020",
month = dec,
day = "13",
doi = "10.1117/12.2561644",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Ramon Navarro and Roland Geyl",
booktitle = "Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation IV",
address = "USA United States",
}