The Simons Observatory is a large international experimental project that utilizes ground-based telescopes installed in the Atacama Mountains of South America, Chile. 

Its primary objective is to achieve a wide range of scientific advancements, including precision observations of the polarization of the cosmic microwave background (CMB) radiation, leading to insights into inflation, neutrinos, and the large-scale structure of the universe. 

In the Sakurai Laboratory, we are responsible for the development of systems such as the sapphire half-wave plate system using superconducting magnetic bearings, optical elements with anti-reflection structures, as well as data analysis.

• The world's largest ground-based CMB experiment, led by international collaboration with over 300 researchers from around the world.
• ~100,000 superconducting detectors to comprehensively observe the universe with multiple large and small aperture telescopes, achieving broad coverage and high resolution.
• The Japanese team is involved in various aspects, ranging from the development of instruments for small aperture telescopes (SAT) focused on primordial gravitational wave searches.
• A reinforcement plan led by Japan for the development of one additional SAT is currently underway.
• Japanese institutions: Suwa University of Science (Sakurai Laboratory), the University of Tokyo, Kyoto University, Tohoku University, and the High Energy Accelerator Research Organization (KEK).