Optical design of an image slicer for the low-dispersion spectrograph of the Chinese Giant Solar Telescope

To address the observation requirements of large field-of-view and high spatial resolution for the Chinese Giant Solar Telescope (CGST) low-dispersion spectrograph, an optical design scheme for an image slicer system is proposed. This design divides the rectangular 50 arcsec × 20 arcsec field-of-view at the telescope focal plane into four 50 arcsec × 5 arcsec sub-fields, each sub-field undergoes optical reconstruction through its independent collimator-camera system (F/36-F/25.79), achieving vertical alignment and focal reduction of sub-fields to form a pseudo-slit, and utilizing tilt mirrors for scanning ultimately enables simultaneous acquisition of spectral data with both a large field of view and 0.05 arcsec high spatial resolution. This design effectively resolves domestic manufacturing challenges for an image slicer featuring hundreds of elements, multi-angle configurations, and compact dimensions, while delivering effective technical support for the engineering implementation of CGST. This design solution can effectively solve the problem of hundreds of units, multi-angle configurations, and domestic processing technology for small size image slicer, while delivering essential technical support for the engineering implementation of CGST.