The primary design of a 1-meter infrared solar telescope

As the ground-based support facility of Chinese Space Solar Telescope (SST), the 1-meter infrared solar telescope will be the largest solar telescope in China with unprecedented angular resolution and high polarimetric accuracy, covering the spectral range from 3000 into the near infrared to about 2.5μm. The telescope is a 1-meter aperture, "polarization-free" concept based on a modified Gregorian optical system. A high precision pointing and tracking system, a thin entrance window and a vacuum light path, will provide the telescope near diffraction-limited performance in the infrared. Two sets of spectrograph systems will be mounted on it according to the different scientific objectives. A fast polarization modulator will be located close to the secondary focus of the system. The telescope will be sited on the lakefront of the FuXian Lake in Yunnan Province which often offers excellent seeing. The paper presents the primary design of the facility for high resolution observation of the Sun with high polarimetric accuracy.