Speaker
Description
Image slicers are becoming an increasingly dominant integral field unit (IFU) technology and will be a key component in a number of upcoming instruments for 20-40m class telescopes. They offer efficient use of the detector space, high throughput and simpler routes to coupling with high dispersion spectroscopy. For ESO’s upcoming Planetary Camera and Spectrograph (ELT-PCS) instrument, which aims to detect rocky Earth-like exoplanets at extreme contrast ratios, image slicers are therefore a highly appealing technology for its integral field spectrograph (IFS).
A prototype “twisted” image slicer, developed at Oxford as part of R&D for ELT-PCS and manufactured by Canon Inc., eliminates the need for anamorphic optics by generating spatially and spectrally Nyquist-sampled pseudo-slit images at the detector while retaining square spaxels on-sky. The lack of anamorphic optics simplifies optical design and reduces aberrations in the system, providing an advantage for reaching high contrast. This talk will provide an overview of the twisted slicer development and integration within the ELT-PCS integral field spectrograph testbench at Oxford. We will discuss the various techniques for spatial and spectral calibration implemented to convert the 2D detector images to 3D data cubes. Finally, data cubes and contrast measurements from the testbench will be presented to analyse the performance of the twisted image slicer in an IFS for direct imaging, and future plans for integration of the IFS at ESO Garching behind the GHOST XAO testbench will be outlined.
