@inproceedings{6c476b9d03b94a579015772de1553a6e,
title = "Multi-core fiber-fed integral field spectrograph (MCIFU)-III: An ultrafast laser inscribed photonic reformatter and mask",
abstract = "We report on the conception and the fabrication of a 3D photonic reformatter of 73 waveguides and its associated opaque mask in a wide collaboration to develop a multi-core fiber-fed integral field spectrograph (MCIFU) centered on the Jband. The reformatter is a 3D structure that light from the input quasi-hexagonal multicore fiber is spread out by rearrangement to avoid individual core spectra overlapping when the light is dispersed. The reformatter is fabricated using ultrafast laser inscription (ULI) in a borosilicate glass of 20 mm length. Using a similar ULI process, a 73-hole mask was fabricated in silica glass that precisely matched the waveguides at the output of the reformatter. The output surface of the mask was coated with a 120 nm layer of chromium to block scattered light generated in the bulk material and enhance the signal-To-noise. All inscribed waveguides, characterized using a stable laser centered at 1310 nm from the multicore fiber to the output mask, present consistent single-mode output behavior with a maximum throughput exceeding 60%. Over the 73 cores, the average throughput was measured at 40%. First observations of the full MCIFU device during on-sky measurements have shown promising results to the potential of this novel fiber integral field unit. ",
keywords = "Astrophotonics, Exoplanets, High contrast imaging., Integral field spectroscopy, Multi-core fiber, Photonic reformatter, Ultrafast Laser Inscription, Waveguides",
author = "Pike, {Fraser A.} and Aurelien Benoit and MacLachlan, {David G.} and Ross, {Calum A.} and Harris, {Robert J.} and Haffert, {Sebastiaan Y.} and Itandehui Gris-Sanchez 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.; SPIE Astronomical Telescopes + Instrumentation 2020 ; Conference date: 14-12-2020 Through 22-12-2020",
year = "2020",
month = dec,
day = "13",
doi = "10.1117/12.2559197",
language = "English",
isbn = "9781510636897",
series = "Proceedings of SPIE",
publisher = "SPIE",
editor = "Ramon Navarro and Roland Geyl",
booktitle = "Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation IV",
address = "United States",
}