An integral field spectrograph (IFS) camera may help fulfill the exoplanet characterization goals of a future Habitable Worlds Observatory. We will design a next-generation IFS prototype to be installed at on the DST2 coronagraph testbed at JPL's High Contrast Imaging Testbed facility. This new IFS will support TRL 4-5 demonstrations of IFS operation with coronagraphs at contrast levels needed to obtain the spectrum of an Earth-like exoplanet.

During 2023-2024 our team leveraged our engineering experience from the PISCES and WFIRST/Roman project to complete an IFS optical design for the DST2 coronagraph. We are currently working through a final iteration of the mechanical design (bench, optic mounts and stages, enclosure, and other supporting hardware). We identified a commercial CMOS package to serve as a detector, and we have begun to procure custom optical components (relay mirrors, prism, and lenslet array).

In early 2025 we will assemble and align the IFS:

1. Characterize and add metrology references to the IFS optics (powered relay mirrors, prism assembly, collimator lens group, imaging lens group, and alignment flat).
2. Use a theodolite, FARO arm, and an interferometer to align the IFS optics in the ExoSpec Lab.
3. Align the detector for best focus and verify the optical performance with calibration data sets:

   • Scanned wavelength monochromatic flat fields obtained with a super-continuum laser

     source and integrating sphere.

   • Broadband Airy disk image using a super-continuum laser source and a fiber collimator.

In the second half of 2025 we will ship the IFS to JPL for integration with the DST2 coronagraph testbed:

1. Verify the post-shipment metrology of the IFS optics.
2. Use an interferometer installed on the DST2 testbed, and a flat return mirror, align the IFS benchto the coronagraph optical beam.
3. Adjust the alignment of the three mirrors at the IFS entrance (two powered mirrors and one flat fold mirror) to focus the coronagraph image at the center of the IFS lenslet array.
4. Align the detector for best focus and obtain optical performance verification data in ambient air with the DST2 super-continuum laser source.
5. Verify the optical performance of the IFS with the DST2 coronagraph system under vacuum.

1. Advance technological readiness for exoplanet spectroscopy with the future Habitable Worlds Observatory: Build on the exoplanet spectroscopy laboratory demonstrations that were carried out during the development of the Nancy Grace Roman Space Telescope Coronagraph Instrument, and push the performance envelope toward the requirements of the next flagship observatory.
2. Support experiments for emerging coronagraphic techniques: Enable multi-wavelength laboratory tests of starlight suppression with novel coronagraph masks, active optics, and wavefront sensing and control algorithms.