From Colors to Chemistry: A Combined Lenslet/Slicer IFS for Medium-Resolution Spectroscopy

TL;DR

This paper introduces a hybrid lenslet-slicer integral field spectrograph design that combines the advantages of both architectures to achieve high spectral resolution with minimal aberrations, suitable for exoplanet characterization.

Contribution

The authors present a novel lenslet-slicer hybrid IFS design validated through lab performance, enabling improved exoplanet spectroscopy with high resolution and minimal aberrations.

Findings

Successful lab validation of the hybrid IFS design.

Achieved high spectral resolution with minimal optical aberrations.

Potential application for future exoplanet imaging instruments.

Abstract

We present the design and lab performance of a prototype lenslet-slicer hybrid integral field spectrograph (IFS), validating the concept for use in future instruments like SCALES/PSI-Red. By imaging extrasolar planets with IFS, it is possible to measure their chemical compositions, temperatures and masses. Many exoplanet-focused instruments use a lenslet IFS to make datacubes with spatial and spectral information used to extract spectral information of imaged exoplanets. Lenslet IFS architecture results in very short spectra and thus low spectral resolution. Slicer IFSs can obtain higher spectral resolution but at the cost of increased optical aberrations that propagate through the down-stream spectrograph and degrade the spatial information we can extract. We have designed a lenslet/slicer hybrid that combines the minimal aberrations of the lenslet IFS with the high spectral resolution of the slicer IFS. The slicer output f/\# matches the lenslet f/\# requiring only additional gratings.