VisIRIS: a visible/IR imaging spectropolarimeter based on a birefringent fiber-optic image slicer

摘要

High-resolution imaging spectropolarimetry in the visible and infrared wavelengths is the most effective and accurate observational diagnostic tool for many astrophysical problems, but many among them also require a spatially resolved two-dimensional field of view. However, it is difficult to achieve simultaneous three-dimensional (x, y, and λ) coverage using instruments with a conventional design. A conventional spectrograph achieves three-dimensional coverage either by scanning a tunable filter through the spectral window of interest, or by scanning a diffraction-grating-based long-slit spectrograph through the target region. Scanning in either spectral or spatial direction unavoidably degrades the quality of the data, and is time consuming. This paper describes a new visible/IR imaging spectropolarimeter design based on a novel birefringent fiber-optic image slicer and multiple-slit spectrograph. With this design, simultaneous 3-D imaging spectropolarimetry of astronomical objects with a large field of view and high spatial and spectral resolution can be achieved.