On April 10th, 2017, a seminar on the Chinese twelve-meter Large Optical/Infrared Telescope (LOT) optical system design was held in Nanjing. More than fifty senior experts from Peking University (PKU), Tsinghua University (THU), Nanjing University (NJU), Beijing Normal University (BNU), University of Science and Technology of China (USTC), Institute of High Energy Physics (IHEP, CAS), National Astronomical Observatories (NAO, CAS), Shanghai Astronomical Observatory (SHAO, CAS), Purple Mountain Observatory (PMO, CAS), Yunnan Astronomical Observatory (YNAO, CAS), Nanjing Institute of Astronomical Optics and Technology (NIAOT, CAS) and so on attended this seminar.

The seminar has included both the NIAOT LOT optical system design reported by Prof. Xiangqun Cui from NIAOT, CAS, which has already passed through the planning selection for the 13th Five Year Plan arranged by the Chinese National Development and Reform Commission, and the American LOT optical system design from the University of California Observatory (UCO), which was introduced by Prof. Ming Liang. According to the planning guidance and instructions of the 13th Five Year Plan for the Chinese major national science and technology infrastructure projects and after serious discussion and comparison, the assembled experts held a unanimous belief that the NIAOT LOT optical system design has the characteristic of times value, Chinese characteristics and creativity, advantages of wide universality, and it can satisfy an extensive need to science requirements. It is better for the needs of both the recent development and the long-term development. Even after the construction of futural international 30m class astronomical optical telescope, there are also of prominent advantages and competitiveness without extra difficulty to manufacture. In a secret ballot organized by the seminar, all the experts were unanimous in their firm support of the NIAOT LOT optical system design to be the final LOT optical design.

China has developed an overall plan for the layout on Chinese major national science and technology infrastructure projects, and these projects are constructed by the support from the subject of high-level innovation in order to promote the strength in discovering the unknown world and universal laws of nature and bringing about technological change. They are also large and complex scientific research facilities or systems, which are opened to the whole society providing service for long-term high-level research activities, and are national public facilities of great international influence.

The Chinese LOT is a major astronomical observation facility jointly initiated and promoted by the Chinese astronomers. It has already been included in the planning for the 13th Five Year Plan for the national major science and technology Infrastructure projects. It is planed to start construction by the end of 2018. After its completion, LOT will be one of the core infrastructures, which is necessary for astrophysical research, and it will greatly enhance the Chinese all-round capabilities in important astronomical discoveries and international competitions in astronomy.